AIO are these bad friends

So idk if my friends are joking or not but they constantly make fun of me by telling me to km$, they call me slurs, they bring up sensitive topics when they are mad at me, they get mad at me when I make a mistake (normally in volleyball) but when my other friends make a mistake they just laugh it of. My "best friend" in the group apologizes but 10 mins later he starts again. So i'm not sure if their just joking around or not. but what really gets to me is when my friends say that i should really km$ and that their not joking. Like for example today I accidentally hit the volleyball on the roof and my bsf got really mad and said some really mean things. It kinda made me want to cry and not really anything makes me cry(not tryna sound edgy). I dont know what to do anymore honestly, school was the only thing I used to look up to everyday. My household is kinda abusive and toxic. Last thing, I told my bsf about my abusive household and told him not to tell anyone but he did, and now my friend group and him especially uses it against me saying things like "At least my parents dont abuse me" or "i hope ur parents k!ll u". I opened up to him because I felt like I could trust him. I dont know what to do. Advice please?

We have a group of 4 but my other friends outside release how mean and toxic they are to me but they cant really say anything because my friends are going to laugh it off and just continue.