Am I right for leaving him?

My boyfriend of seven months and I fell madly in love, but he is a Freshman at the Citadel so he changed a month ago. He used to write me love messages, but stopped texting me, calling me, telling me he loves me all in a month. He never responds to any wall posts I leave for him on facebook, but he constantly posts on another girls wall. he doesn't even have his relationship status displayed...you have to view it on my page. I have gotten connected with his family too. I have confronted him about the posting and he has yet to do a thing to change it. I still love him, but I feel in order for my life and grades to remain pleasant I must leave him. I know it's the obvious thing to do, I just want to hear what other people think. My friends all hate him now too because of the posts on the other girl's wall.