I am so sorry. I understand, I really do. Please feel free to read my threads, as they may offer some insights for you.
A couple of things. Your H may be in mid-life crisis. You said you had been married 20 years, so that could put him in the right age range. The things you are describing that your H is saying sound very MLC to me. Read the MLC board, there is really good information there, and see if it fits. It has helped me be more compassionate to my H, to realize that he is in a big life transition, and may not be consciously aware of it at all. Just that something's very different and it's scary. Try to be compassionate.
The good news is, your H wants to stay home and work on the M. I wish so much that my H was saying that to me! You have children. If you actually work on your M, you have a chance of making a better life for them. Take this seriously. You could change what is possible in the lives of your children and your children's children, by the choices you make today.
Regarding living together or apart: I kicked my H out when I found out about the A, right away that night. In some ways, I wish I hadn't, because lack of contact makes it harder for me to see that we are making progress - it is going sooooo slow, and I sometimes think it would be going faster or better if we had more contact. But on the other hand, in the beginning, I couldn't have DBed with H around. I cried buckets and buckets and was so needy and traumatized, and that would have worsened everything. I don't think I could have created enough space for myself to DB with him here every day and night. So the answer is, it depends.... Can you keep him in the house, but create enough getaways for yourself to become and remain centered and DB? That would be my preference, and I could definitely do that now. The key is, take care of yourself. My advice is though, whatever you do, don't do it or decide anything until you are calm. It might take a few weeks, but try to center yourself. It is the emotional out-of-control decisions that aren't satisfying, IMHO. In most of the books I've read, it says stay in the house together if you can. But don't do it if you can't be civil and DB. Just give yourself a few weeks to settle down a bit, then it will get clearer.
If you can, I suggest you both get to a MC right away. H wants to work on the M. You need tools and support. Catch the wave while it is here. Find a solution based therapist and make an appointment. BTW, don't let money be an issue. It will cost you A LOT MORE if you don't work it out and D. And your kids will pay the most of all.
Hang in there. And keep posting.
PositivelyListening ************************************** When one door of happiness closes, another one opens; but often we look so long at the closed door that we do not see the one which has been opened for us. - Helen Keller