You already know the facts that the boy you're in love with is bad. You KNOW that he would cheat on you too if you were ever to be with him. You need to love yourself. Your feelings are looking for trouble and if you can love who you are as a person, you can find it in you to love your boyfriend. He's great! And you know it! Move on forward. Don't think about the past, you're thinking too much!
Time heals all. Don't look for the bad boy, and these feelings of love will go away, you just got to find the will power. Plus, you've only been with your current boyfriend for a month. Give it time, you'll fall for him. Trust me, I was in a kind of similar situation as you and ended up going around with my boyfriend 4 years!