Well... I think I would chat with a lawyer just to know what my options are.
Where I lived, there was such a thing as "legal separation" -- meaning the minute I was out of the house I was no longer responsible for any of his expenses or behaviors, etc. That was what I needed while I waited for the divorce to be final (in my case, there was no going back, the only "trial" that was discussed was the kind you have in court).
There was also in my state something called a "separation agreement" -- meaning we basically could hash out everything as if we were divorcing, and after we agreed to it, we would have a year to have a "trial divorce" -- living separately, according to the agreement. And then after a year, we could either move back in and continue to be married and the agreement would go away, OR the legal separation agreement would become the terms of the divorce (which would then be happening without any further negotiations).
I think I would want to know what my options are, legally. And I think I would also get that 15-year-old into counseling asap. Hating your father that much is hard on a kid.