I lost an employee to cancer a few years ago. He was 40, with 4 kids- a 2 year old and a 4 year old. His wife asked my why God did not answer her prayers that her husband be saved. In a recent sermon, our priest talked about that topic. He said sometimes when you ask God to do something, the answer is "no." Plain and simple, God said no.
Now why he said no is the challenge. If the marriage was a bad environment for the kids and a constant grind for you, maybe the answer is that God wants mommy and daddy to be happy.
Bless you in your challenge.