Homophobic mom?

My mom doesn't believe that I'm gay. Any time I mention or make a joke about anything related to me being gay she turns it into a huge argument because I "don't get it" and I'm "too young to understand" she acts like I'm just some stupid kid. She always has some reason to yell that is apparently supposed to suddenly convince me that I like men. Why does she do that? Why can't she just respect me and my sexuality? She claims to be an LGBTQ+ supporter but she won't support me and she thinks that my gay and trans best friend is just "faking it". I called her out for being homophobic the other day and she told me that she was severely offended and just wanted me to know everything about my situation before deciding. Which would actually make sense, even though its not something I can just decide on, If she was providing me with information in a supportive way and simply trying to inform me. Instead she is yelling and basically trying to conform me. But then again, maybe I'm just being overly emotional. I know I don't have it as bad as other people do in this community, after all it's not like she beats me for being gay, but it still hurts to not be validated by your own family... is there any way that I can talk to her about this? Get her to understand that in order to be a supporter you actually have to show some support

(Someone asked how old I am and sence I cant answer to comments and stay anonymous at the same time, I'll just do this and tell Scarlett that I'm 15)