I'm confused... you told him you wanted to separate and he said "no"?

I guess I don't understand how this actually plays out. It seems like if you want to leave, you leave. He doesn't get a vote. He doesn't get to veto it. This is a unilateral decision.

Do you want to leave? Or was it just a feeling, a response to the heat of the moment?

It sounds like a really painful situation, and if you've tried therapy, tried working it out, and it's not working... then it's not working. I'm not married, so I feel a little out on a limb giving advice, but I think you have to decide if this... him as he is today... is something you're OK with and can make peace with/live with. If not, if it's unhealthy for you, then you need to start thinking about getting out.

Maybe feel out your options? Like... do you have your own therapist to talk to about it? Can you meet (maybe they offer free consults?) with a divorce attorney to see what your options are right now?

It just seems like an awful situation to stay in... feeling miserable, not valued, not heard, and with no hope of things changing. I know that we can't really expect others to change (we can only work on ourselves), but it sounds pretty toxic?