I feel like I'm going to end up miscarrying if I don't leave..

I'm 9 weeks pregnant and currently living with my fiance's dad and his wife because our house had been condemned for black mold. I also have full custody of my 2 year old son as his dad walked out shortly after he was born. Anyways things were borderline okay for the first week, then all of a sudden his wife starts accusing me of taking her stuff. First time was her wedding ring(she hid it in her purse because his dad found it and confronted her.) Then it was her toothpaste was missing(same situation.) I kept trying to ignore it because I obviously knew it was for attention and to try to turn his dad against him. Then she says my fiance's dad needs to choose between us and her. I needed a break from the stress so we stayed with another family member for a few nights, came back yesterday and my ultrasound pictures were missing along with my important child support information I was supposed to send back in. I always keep all my mail in one spot and my son can't reach it so we know she took them. Found one ultrasound picture ripped up in the garbage. Told my fiance I just need to go stay with my mom until another house comes up and hes mad about it but wont go with me... I don't know what to do anymore.😭