Don't have an appetite to eat...?

Gf broke up with me because of my height but she actually busted used that as an excuse for another guy, not only I'm not confident now but I'm also very heart broken, I was always nice to her, she went on a date twice with 2 different guys and now there's a third one, she says because I always get jealous well who wouldn't be when all the things she did to me ruin her trust for me, she meant so much to me, I even messaged her parents something meaningful and long and they just call me a creep like what, I don't know why some girls are like this, I guess nice guys just finish last.