I can definitely feel your pain, man... I was married to a "Christian" woman for 20 years who kept telling me I wasn't a Christian because of every little fault she could find. Get mad in traffic? Obviously not full of the Spirit. Drink too much at a party? Not a Christian. Lose your temper when working on a project? Not a Christian.
In the end, she ended up starting a romance on Facebook with an old boyfriend and asking for a divorce. I guess that's "Christian"...??
I was pretty bitter and went to a Christian therapist who set me straight in regards to confidence in my faith. I KNOW I'm saved by grace and no one can take that away from me. I've been divorced for three years or so now and have found a church I am ready to invest in spiritually and financially.
It's not easy, though. I've found that most, if not all, churches are very much centered around the ideal of a Christian man and a Christian woman falling in love in their 20's and getting married, having kids, and raising a family. There is no end of support in today's church for the family.
There is also no end of support for the elderly, for the teens, for the college singles, etc, etc...
Try being a single guy in your forties and finding a church group for you. There is none. I went to a church that instead of having a variety of Sunday school classes, had "home groups". I was assigned a group based on my geographic location and work schedule. I went a few times and the people were great, friendly, loving Christians. But... They were all married couples raising pre-teen kids. They organized group activities around kid-friendly activities like bonfires and bowling.
It was not a good fit. I went to a church 3 blocks away from me with a great pastor and sound teachings. It is a small church with maybe 40 people there on Sunday. All the members are either young families, elderly widows, or old couples. I just didn't fit in.
I avoided going to church because I simply felt like an outsider. Then I caught myself deciding what church to go to based on how many single women there were instead of the quality of the teaching. I rebuked myself and decided on a larger church with rock-solid teaching and a diverse congregation. I no longer view church as a place to go to meet women, but as a place to go to be fed spiritually.
And don't go to the same church your ex-wife and you went; that will be a disaster. I moved 1200 miles away from where my ex and I lived the last seven years of our marriage.