afraid to tell my bff i’m still trying with my bf

hi, a lot happened with my bf and i. mostly he lied to me about some stuff but he started therapy and is taking meds now. i decided to try to give him another chance because he’s trying to be better (hopefully). my best friend told me to break up with him like last month, but i never did. for a bit we were but i decided to try again with him. but i haven’t told her because im worried she won’t be my friend anymore or something. i’m basically worried about how she’ll react. thx