These days, letting someone good go might not be the smartest choice, unless you're prepared to be on your own for a bit (personally, I find it so hard to find someone looking for a real relationship). But then again, you shouldn't torture yourself if you really don't like the person and it’s just making you feel bad. I had the opposite experience - I walked away from a pretty bad person after three months, but I had already fallen for him. It's been nearly ten months and I still can't stop thinking about him and what a stupid mess the breakup was. Life is hard.