Should I wait around for her or break off contact?

Okay, first off, doing drugs and thinking you really ****** up doesn't make you a bad person. So don't think it does. Second, I honestly believe that just because she was your first love and you didn't know any others doesn't mean that you don't love her. I think you do, from the way you are speaking about her. I believe maybe you are definitely confused and just maybe you need to give her space. I know that might be hard, considering you're in love. Trust me, I've been there. You never know, maybe she still has major feelings for you too. Maybe she is just going with this other man to get over you after loving you for so long. But I can't speak for her because I don't know her side of the story. I may be totally wrong. Also, don't beat yourself up for "waiting too long". There's nothing you can do. But I don't think you should cut contact. Even if she IS in love with this other man, it doesn't mean you two have to stop talking or not be friends. And maybe that's what is good for you and for her. Who knows? Maybe eventually, she'll come out and tell you she still loves you. But if she IS in fact in love with this other man, you have to be a man yourself and respect her decision. You can't help who you fall in love with. Hope this helped at least a little bit. :)