First and foremost, I want to praise you for your devotion to the family....I too am a family woman who gave up her reign to "comfort" HIS family, at the cost of my own....OUCH!
It is amazing how two people can live the same life together and get two completely different experiences from it...I don't know if you have siblings, but if you do you may recall that you lived the same life, in the same home, in the same dynamic but came out of it with different blessings and unmet needs....marriage is like that too.
You are at a junction in your life where you CAN choose to let go...Your children are not children and you do not HAVE to sit back and watch him destroy himself...Nor do you have indulge in his family dynamic...that's their dysfunction...let them have it!
You have your own source of income...now release your burdens! Be free! If the worst of it is that you let the house go....well things could be MUCH worse...

I really can't relate to your situation, The flea(EX) was and still is the provider for my home. I was and still am a stay at home mom. He still pays my bills even though we are divorced. I did do the parent thing all by myself, I would take the kids over to his parent and entertain his parents, while he entertain himself with other women.

The thing about the kids, they will side with him because he is sick and you know it. Sooner or later they will see it is not exactly what they wanted. Don't stop giving your ex financial support but make sure you have proof, you have been helping him.

If there is something I have learned from all this is to stop caring what other think of me. Those thoughts only make you sick and make you second guess yourself. If you want out, just get out. Don't let anything tell you different. Take care and keep us posted.