Does anyone else here have serious problems with their in-laws?

DH's family is just so unbelievably dysfunctional I cringe at the thought of ever speaking to or seeing any of them. Except for his sister, who doesn't speak to anyone in the family but DH and I. There are some really serious issues there, and I don't want them having anything to do with my family now.

I am fine with never seeing/talking/dealing with any of them, ever again. Unfortunately, this is a lot harder for DH. It is like they have this sick power over him to make him feel guilty. I cannot stand it!

DH's birthday is in 2 days, so suddenly his mother is calling him repeatedly (seriously the first time she has even remembered his birthday in the 10 years we've been married.) She is like a tornado, whipping in to his life, leaving a mess, then disappearing. Every time, he expects something different, but it is always the same with her. I just can't stand how bad it affects him.