I don’t know what to do anymore

I’ve been with my boyfriend for 4 years.

Since I was 16, I’m 20 now. We started off distance and then finally once we both graduated moved in together into a small apartment. Once that lease was up we really couldn’t afford living in that area so we moved in with my parents to get our money back up after just getting a car. He lost his job for a bit and I started school so everything just turned into a longer stay after awhile. We have been here almost a year. We both finally got full time jobs. He always had a good relationship with my family until we moved in with them. Now he hates my parents. Can’t even hear their voices in the house without yelling at me and telling me that they’re pieces of shit. Hates when my 5 year old brother cries. Every little things makes him mad. He wakes up mad, goes to sleep mad. He doesn’t have a good relationship with his family and I couldn’t imagine and I try being super understanding. He told me today that “I see why your sister has no friends at school” she’s in 7th grade and gets bullied everyday. He knows this so for him to say that hurt my feelings. I’ve became so distant with my family the past year. I don’t even go out of the room anymore to talk to them because I hate the argument it causes between my boyfriend and I. I don’t know what to do. Has anyone else ever been in a situation like this? Please help, any advice would be nice. Right now I feel like I’m losing my mind.