Just leave him alone. Let him get over the breakup on his own, and don't get in touch with him just because you want to make yourself feel better. If you know you did the right thing by breaking up with him, you have nothing to feel guilty about.
I'm 18 and my ex bf just broke up with me 3 days before our 1 year but we have I feel you its sucks because my ex boyfriend left me behind tell me its my fault.