Good for you on the weight loss, Mish - it is NOT easy. I have to do better too. Josh and I are both trying to eat better but it is harder when you're away from home.
The only thing I can say about his lack of effort and your unwillingness to talk to him about it is that I did the same thing with my ex for years. And it never got better. And I swept everything under the rug. And now - when I look back - I can only say that I am so glad that things didn't work out with us as I divorce busted. Forgiving the affair would have been SO difficult but to feel that he really didn't care that much about the quality of our lives would have brought it all to an end sooner or later. For me- I'm glad it was sooner. Or I wouldn't be living the life I want.
The church group could be good. Keep trying. And how about a counselor to help you through the changes you want to make?