Courtney - I'm going to be blunt here, because I think it needs said. You weren't the only one who didn't get married. I realize that you're feeling your freedom and "sowing your wild oats" and all that, but there was another heart bruised by your calling off of this wedding and you need to start considering his feelings as well.
Adam never did anything to hurt or betray you. His family did. You need to remember that so you don't take it out on Adam and walk all over him with your new found freedom. He's gone from being in what he felt was a loving relationship where he was getting married, to his girlfriend suddenly ignoring his feelings and going out until 1 a.m. I can only imagine how confused, hurt, and worried he is.
You're sending mixed signals and you need to not do that. Either you want to move on from Adam, and you do. Or you want to work on your relationship to make it better, and you commit to that. It's a grown up world, not high school. You don't get to sit on both sides of the fence. Please consider how shocking this must have been for Adam in the decisions that you make.
I'm happy that you're happy, but when you continue to hurt someone that you once (or still do) care about, that happiness comes at a cost.