Incapable of being in a relationship?

I was dating this guy for a year and I loved him so much but I broke up with him for stupid reasons and we are talking again but I feel like I can't be in a relationship without ruining it. I want a relationship and everything that comes with it but then again I want to be free to do what I want.. am I not capable of being in a relationship for longer then a year? Should I go to therapy or something about it I don't know what to do.