I can't get over my ex

I'm currently in a relationship but bent over my ex. He's also in a relationship. He left me in January 2015 cause we were in a long distance relationship (Canada - London). He broke up with me and immediately started dating this new girl. A year later now we talk every other day about a future, our past, sext and so on. I just called him for the first time since we broke up and his voice sent waves of butterflies through me for over 20 minutes.  I know I'm in deep but I don't know what to do.