I think that we might give up

My husband and I have spent...10+ years fighting on behalf of his kids (11 & 14). They live primarily with us but that is constantly being tested. We are running out of vigor. His ex-wife doesn't really work (part-time as a bartender) so she has a lot of time & energy to spend on fighting us. She is at best really screwed up with borderline personality disorder, at worst a total sociopath.

We have a 4-year old son with autism and a nearly 5-month old together. We are becoming exhausted. Lately we have been considering moving far away and letting the chips fall where they may.