Crush Likes Best Friend

I (15M) am new to reddit so this is my first post. My crush (16F), we’ll call her Sarah, likes one of my best friends (16M), we’ll call him Dominic. So Sarah and Dominic have been talking for a while but my Sarah either can’t tell if she likes him, or is hiding that she likes him. I’ve been super supportive of them and I want the both of them to be happy but it just makes me mad to see them cuddling at group events or slow dancing together at prom. He knew that I liked her when he started talking to her, but since she obviously liked him more, I told him he could go for it and I wouldn’t care. But I actually really do care. She doesn’t know that I like her (at least I’m pretty sure) and I don’t think she would go a guy like me. I’m more loud, weird, and flamboyant(?) if that’s the right word. Dominic is athletic, confident, and we’re both funny but in different ways. I just don’t know what to do with myself. Do I tell Sarah or Dominic? Or do I just wait until they either do or don’t work out? I have had feelings for her for a year now and I simply don’t know what to do. I don’t even know if there’s anything I can do but I really don’t want to watch them date while feeling sorry for myself.