Danny, I don't know how I missed this thread, but I have some words for you.
You're doing GREAT! The devil's given you some tremendous sorrow, but you've leaned on God and overcame. Reading over your story, I was moved to tears on several occasions. You're truly a testament to what God expects of us as Christians, and your personal story is a testimony so powerful that it should be shared.
Don't lose your faith, keep leaning on God, and that fire will come back. Keep in mind Ecclesiastes 3..."To everything there is a season, and it is tied to every purpose under heaven." Perhaps your season for puppet ministry is over...Or perhaps, your season of sorrows will ultimately light a spiritual fire that's almost blinding. Pray on it, see what God's will is there.
My husband underwent something very similar to your situation when his first wife left him. He, too, ended up with sole custody of his kids (his son was 2 1/2, and his daughter only 8 months old) after a very nasty discovery of
four different men in his wife's life, and the subsequent nasty divorce. The mother walked away, and stayed out of the kids' lives for three years. During that time, he prayed, and showed his kids pictures of their mother, so that they would know who she was if she returned.
His ex-wife describes those three years as "nightmarish". She did things she now knows are wrong, got mixed up with the wrong crowd, developed a few addictions, and caused immense pain both to herself and to others.
At the end of those three years, my husband received a phone call from her. She'd been living with a man, who'd beaten her so savagely that she'd lost the child in her womb. My husband immediately went to the home, helped her pack up, and moved her to a safe place. During that episode, my husband asked her to come back to him and the kids. She refused point-blank.
He continued to pray.
After that, she came around a bit more. She visited the kids, and straightened herself out. She attended school, got her degree, and she finally met a good man who could give her what she needed in life. After she married, my husband started dating again. He and I met. Likewise, we fell in love and married. I met his ex about five months before he and I married.
He continued to pray. I started to pray with him.
These past four years have blessed us all. My husband, his ex, and I all co-parent the kids together. I'm blessed to have a close friendship with her...A friendship so close that, in times of trouble, she doesn't hesitate to call. We giggle over the kids' actions, cry together when they're in trouble, and work together because her kids won't suffer if we do so.
And last month, she accepted Jesus as her Savior!!!!

I keep grinning when I think about this, because she's going to church religiously, being a better role model for her kids, and even buying them Bibles and discussing the Word with them! God's put a song in my heart every time she and I speak now!
You are where my husband was those many years ago. Please don't give up faith, continue praying for your ex without ceasing, and love those boys with every breath of your being. God doesn't leave us or forsake us, and it hurts Him when we're not in His will. That goes for your ex, too. Forgive her in your heart, and be prepared, because there will come a day when she'll turn to something different...But she'll have to hit rock-bottom first.
Your life will change...Again, it's that season thing. But whether your life of seasons will bring your wife back to you, or if it brings a woman who can appreciate all you have to give, and complement you in your life, just be content that God won't leave you to flounder.
I'm in a family that's living proof that God can take the horror you and your boys are experiencing, and turn it into something of such joy that your heart bursts when you even think about it.
God bless you.
And keep praying for her.