I had sex with my brothers best friend.

I’ve been liking this boy since I was 12 . That was the first time we met . He is 2 years older than me and one of my brothers best friends . We’ve always liked each other. A relationship is something that we agreed would happen later because now wasn’t right time with him being in college and me still in highschool . He came over once and we just kissed a little bit . Btw I’m 17 and he’s 19 now . We’ve had many chances to hang out but I’ve always said no because I think my brother would resent me . A couple days he took me out with him and went to his house . I never anticipated anything happening only fantasized . Before I went over to his house I was super nervous to see him , one of his text read “ I come in love and care, no I’ll will towards you , just unsure of what the future holds” but I was still shaking when I sat in the chair Bc I knew the feeling was there . That day , we had sex and now I feel terrible . I can’t tell what he really wants rn Bc he leaves for college on Monday . I can’t just let go and forget . I’ve been head over heels for him forever . But it seems like that’s what I have to do rn . What do I do ?