Scott, i do believe there is promising hope in all this. The promise really is through following direction of God's Word. Follow His direction in this. Dive deeply into devotion (Studying the Bible in multille chapters at a time over days to get an understanding - 30 minutes here, an hour there) Take Ephesians 5 in an open Bible into your prayer closet and seek God like never before.
This is how i see fighting for your wife looks:
1. Fight the enemy - not flesh and blood. How does that look? a. Spiritually, what is the Sword? That's God's Word. Write out passages from different parts of the gospel (within and around thd red lettering). Post it in different places in your house for YOU to read as reminder of your authority in Jesus Christ. (And i've done this.) Quote the Word, espcially those passages such as in Matthew 25, that tell of the devil's and his demons' ending. Speak out from the Word what they will not want to stick around and hear. And believe exactly what you quote. . Pray pray pray with Bible open. The more Word you have, the more equipped you are to confront the attacks of the enemy head-on. For the spiritual warfare of life period.
2. Put your foot DOWN with the one the enemy is using. That would be that old friend of hers. Your fighting is not against him but that doesn't mean you have no authority over how he will bring himself on the scene disrupting the house you gave God to build. Would you let him come litter in your yard? Would you let him take make from your mailbox? Would you let him spread gossip about you within your place of employment imposing a risk on your stability? Well, he's doing a worse violation. Guard what God has given you - your family. Matthew 18 and 1 Corinthians and Revelation 2 absolutely do show how someone has to be outed (after attempts to remedy). Billboard? Idk. Thats up to you. Im more selective with who I'd tell and who i did tell. It wasnt public but it was effective concerning who i told. I stayed mainly within church who i told for accountability. Letting his spouse or girlfriend know is common but only if you have the mindset of going thjs distance. If you don't have the mindset, then don't do it, as resulting andd unexpected challenges may be involved. How much are you willing to take authority - non physically- is the question.
That's not the only way to put your foot down with this man. If you choose more quiet, subtle approach and take that desire to God, don't doubt that God will give you direction. Just be willing to do what God is telling you to do (of course you know that) even if it means aggressive authority. And if God moves on you to be still, then be still and study, pray, study, pray.
3. Deal wisely with your wife. And be gentle, heroic, cool, and calm while tending to your own business around the home, including continuing to be fatherly to your child. Think "gradual" and "longterm" outcome in this sense: Most efforts demonstrating true love toward her will be incredibly GRADUAL. Your efforts are not likely to yield overnight results. So build "brick by brick" some experiences for her to reflect on through time, without telling her that is what you're doing. (In fact, do NOT announce to her what you are doing or what you are going to do. Why? At the rate she's going, she may put her guard up to deliberately ignore you or rationalize something negative. Demons do communicate more aggressively when they've been on a role an somebody is trying to petition for God's intervention.)
Build experiences for her how?
a. If you have nothing to say on that road trip to Vegas tomorrow, play some playlists of soft, melodic music (whether worship or whether wedding songs) to instill into her memory bank for nostalgic purpose. Im old enough to know this to be effective. The possible longterm affect on her: Hearing that music will remind her of pleasant times with you. That takes time. If you want to build experiences for her to reflect upon, build with the attractive "bricks" that will give her fondness and appreciation for memories (sometime eventually becoming romantic memories). Not just the rough "bricks" of trust that she will relate only to a hard lesson learned. Play the same nice playlists when you are doing things around the house, in the yard, or wherever. Play them often. She'll hear them. And on her dullest days, the nostalgic memories will build for the times when she may be alone thinking when a song can come on and minister to her how special you really are. Create memories in a number of different ways subtly with not just music but with memorable dinners (together or not but maybe cooked by your hands), wonderful movies that any lustful scum couldn't bear to watch, and family photos that are priceless.
b. Again, do your business paying attention to other things at home. Without giving her too much space, there's still enough space given to her that will allow her to see you living your life contently with purpose while she can take notice from a far enough yet close enough distance. Put on a tank top, get sweaty working on a car or yard from time to time. Fix the car. Wash the car. Wash her car often and gradually (possibly) start looking like her hero. Mow the lawn. Pay attention to what you're doing and pay attention to activities with your daughter. Live your life with great contentment. She'll eventually notice but she'll probably say nothing about her noticing for a long time. But she will notice.
c. Look her calmly into her eyes when communicating to her. If she doesn't give you affection in such moments, it's up to you on whether you will give her affection. But if you give her only a slight pleasant smile at the close of such conversation and then walk away to do your own business, she will take notice and wonder where the affection is. Do that repeatedly and she will look for it at some point. Is that a game? No. Why? Because mystery is not always a game. Sometimes it's just necessary.
d. If you buy her flowers, for now, don't buy them to hand directly to her only to stand there anticipating a reaction of gratefulness from her. Leave such gifts in a vase on the table or credenza while she sleeps or something, and then go to work. Say nothing about them. And this is concerning any other moderate gift. This is a break-down method. Such gestures done periodically - not too often, not too rarely - help chip away at the walls that shutdown spouses have built up.
e. Again, listen to good sermons on your own without asking she listen. She'll overhear what you're listening to and begin to listen. But the speakers cant be your everyday messenger who is preaching watered down gospel. The true gospel preached will make a difference very likely. Only the true gospel can change a wayward heart.
f. Watch a good movie for your own encouragement. If she joins you, great. If she does not, enjoy. Fireproof (watching it multiple times can give a wonderful different message each time) War Room, etc.
g. Writing the letter Endeavorer is talking about is called a "no contact letter". When my husband expressed that he wanted to save his family, as a condition of me beginning to try reconciling, i had him write such a text in the form of an apology to his former mistress. Apologizing for playing with her head and to repeat exactly what he had told me - that he had only been using her. He did it immediately and very willingly, requesting to her that she not ever call him again and wording as he saw fit. I wanted it to be honorable approach insisting he apologize because im that type of person and cared seeing we ourselves have a daughter we wouldnt want used in such a way. So, if you express wishes she write a no contact letter, maintain genuine approach on how you'll express you want her to do this.
h. You seem to feel you shouldnt have to do tactics to "win her back". I know that feeling. Nobody should have to win back their spouse unless they were the ones who messed up.Thats why it is good to focus on your own advancement as a fit, gym-going man of God, while you navigate this journey discovering the greater man God called you to be. And one day, if comparing herself to you, she may come to see you as the better person and feel motivated to change.
i. Again, research post partum depression. Along with hormones, life itself has shifted and has become less spontaneous and adventurous, which she obviously likes. Now... It's more routine with feedings/diaper changes/housework/moving around/ and sex as a thing to do when you have time. That brings me to my final point...
j. Women like romance that includes sex, among other aspects of it that lead to those final sexually intimate moments with cap of of cuddling. Marital sex can often be so mechanical. A spouse maximizes the opportune moment while there's a chance before either getting quickly washed up for work or drift off to an immediate snoring sleep because of work within the next 8/less hours. Most married couples become familiar with the routine of sex within 2 years after vows are made. To communicate any understanding of that reality to your wife probably won't be as effective as letting her experience a marriage book, cd/online message, seminar, or class for Christians preferably when she is ready to inquire about true marital love. Or if you listen to messages (again within her earshot so as not to invite her to possibly feel pressured to hear), both Jimmy Evans of Marriage Today (marriagetoday.org) and Dr. Tony Evans (archives on oneplace.com) are honorable men of God who preach well on marriage. Dr. Evans' daughter is Priscilla Shire from WarRoom.
All of this is keeping an eye on her inconspicuously. Usually, when you busily don't pay attention to someone significant as a love interest within close proximity in order to fulfill other purpose, they take notice and start paying attention. I don't mean occupying yourself with idle stuff like video games. But doing purposeful things. Again, fixing the car or washing the car with a tank top on. Give her something to see.
How long will this go on? Probably until she grows up or snaps out of it.