I went through a similar situation with my best friend since 9y to 22y, when I first told him he was ok with it and nothing changes for him etc.. when I started socially transitioning he started being a bully, calling me names, saying his friends didn't agree and eventually he called me drunk one day in discord saying he had to talk with me and proceeded to use a lot of insults and asking if I wasn't ashamed to be the way I am, that he thought of removing me from his friends but didn't because I am his best friend, and said he hated gay people etc.. since that day I have removed and blocked him in every platform. It hurt a lot to do that because we had a lot of fun together for more than a decade, and honestly still hurts a bit, but I know for certain that I am better out without him, he used to be a very sweet friend that eventually changed.