Anon, I don't care of you two are working on something that is winning you a Nobel Prize. You have to get out. No story, no story at all, is worth subjecting yourself to emotional and physical abuse to see it through. And trust me, this is coming from a writer. My stories are my babies. But I would drop it like a hot ceramic mug if someone was hurting me.

You can come up with another story, OP. You can start again. Even if you think that's too hard, think of it this way; if you are suffering, your work will suffer for it too. Get out now, start again.