@AndPeggy08 echoing what's been said, your life sounds incredibly challenging and I'm so sorry that you're having to go through it.
A friend had something similar - husband just threw up his hands and bailed (to another country at that). I think it's that old chestnut that is said of men who walk out on children with disabilities or other issues - why do men leave? Because they can. While mothers just plough on. God I had moments when I just wanted to walk out and escape the awfulness but we don't.
DD never had OCD but then with the anorexia developed behaviours that seemed like it to me (but were never diagnosed and I have little knowledge). The rituals around eating, the examining crumpets and bagels to find the most perfectly round, the scoring avocado on toast relentlessly. So many. And now that the anorexia has abated, so they have. There's so much that I thought had become part of her which has turned out to be the anorexia and has now evaporated. Violence, meanness, anger etc.
So I guess I'm saying that the therapist is probably right - you need to plough on with what you're doing and hopefully as the weight goes on, the behaviours will improve. We never had great weight gains - the very most was I think a kg in a week but usually it was more like a few hundred grams interspersed with loses. I got to the point where I was just relieved if it wasn't a loss.
I'm a big fan of judicious use of antidepressants, seeing how they helped DD. Would it be an idea to talk to your GP about some for you if you're not already taking some?