Hello moms I have a big situation on my hands...so my grandmother live with me and my three kids…

Hello moms I have a big situation on my hands...so my grandmother live with me and my three kids going on a year now..for some reason she have something against my seven year old...she always say my son wanna be like the other kids (meaning like my nephews)which he don’t..he just being a Seven year old..she be talking to him crazy..she called him a faggy for hitting one of my nephews..the other day she called him dirty..apt I’m so sick of..I have anger problem real bad like real bad an she know this..I have a good example last night one of my nephew who’s five him and my son the Seven year old was fighting..she gonna tell my nephew who is like 10 11 that my son was hitting his brother the five year old..the way he was hitting my son y’all would’ve that he was fighting somebody in the streets mind y’all this is not her first time doing this to my child..WHAT SHOULD I DO NEXT?