Feeling serious regret after sex with transgender

Okay so quick backstory: I'm 20 years old and consider myself to be mostly "straight" since I would never enter a relationship with a man our transgender woman. I know this is not because of social stigma, ill get into that later on.Anyway, I've been masturbating to transgender and gay porn for about 4 or 5 years now but never went through with anything. Overtime I thought I would (usually through Grindr), the other person made it clear with me that they wanted to kiss, and I can't do that with a man. the idea of that kind of disgusts me, like I wouldn't be able to put myself to do it even if it were forced.I was out of town today and an older transgender woman was on Grindr, so I messaged her. I decided to go through with it, and went over her house. we made out, for like 30 seconds, and it made me extremely uncomfortable so I asked her to stop and we went right to the sex. she sucked my dick and then I topped her. as soon as I came, I felt so much regret like I never have in my life.I've been constantly all day thinking about this and don't know what to make of it.I do not consider myself to be straight, but also not fully "bi" I guess. Im only attracted to womens looks, I could never be attracted to how a man looks. did I make a mistake do you think?