I'm so sorry to hear about H's behavior. He is self-absorbed for sure and until he can unravel his own issues, he'll continue to blame you instead of looking at himself.
As Kerry said, you have a tough road ahead of you. Either you will continue to stick it out and keep holding out for him to finally "get it" or you will move forward w/out him. Either way will be painful and difficult, but only you can decide which path to choose and when.
There will be regrets either way as there is no way forward for any of us w/out regrets. However, we can all use our past to grow for the future.
For you and your children, I can only pray your H will be able to do what is right. However, I too am losing hope in him as well. I hate to say it, but H's road to discovering himself looks to be very, very long.
I will admit that he is making small bits of progress, especially w/his realization he can't handle two jobs any more. That is huge, but I wonder if it is too little too late for your M.