JGB,
Reading your post has made me incredibly sad. I remember when I first joined this site and you were here as Just Getting By...A place my hon was at when he left the farm...just getting by is seems like a place of sadness to me...not progressing or growing...just going through the motions from day to day. I do understand that you are trying to find a more emotionally sound place and taking care of yourself. I have appreciated your honesty and goodness.
Is it possible that your prayers have been answered but not in the way you expected they would? You prayed that you would be happy in your marriage. If God doesn't mess with agency, and your wife has no desire to change, has he worked with you to be able to handle and be happy with the wife you have?
I think personally that there are a lot of LDS people who stay active in the church to preserve the feelings of their spouse.
I personally believe that staying active in the church as a couple helps preserve better outcomes for our children and their children. I believe it is better for our society as a whole.
I find this article by Elder Holland on the rise of secularism thought provoking.
https://www.lds.org/prophets-and-apostles/unto-all-the-world/bound-by-loving-ties?lang=eng
I have spent time questioning my beliefs, knowing I can't know with a complete surety. I do have a hope in Eternal life- that I'll see my Dad again, that we all will continue to progress in the next life and that Christ's atonement will help make up for my many shortcomings.
I hope you will find the hope you need to sustain you and find answers to your prayers.
Take care JGB, You are loved here.