Well during the summer I talked to this girl (marina), but for some reason I totally screwed her over. I went out with one of her friends instead but just recently broke up with her. And now I can't stop thinking about marina and I think I might be in love. One problem, she has a boyfriend now,and I am at the point of hating myself. I can't sleep eat do anything, all I do is think about her. What can I do?

I think you should respect her enough to realise that you screwed up and leave her alone! If you must, you should let her know that you're sorry and you wish you could have another chance - but you're certainly not in any position to ask for her back. If she doesn't want a bar of it then you'll just have to let her be happy with her new boy. Stay friends with her if she'll let you - but you have to understand you're nothing more than that.

Maybe in the future, if she means that much to you, you might get a second chance, but I wouldn't hold my breath.