what to do..?

Don't keep things to yourself. Always end up being a bad idea. Vent it out to someone you can trust. Even a stranger like me, or anonymous through blahtherapy's beta chat. Get your mind off of the guy and focus on yourself and your interest. Be happy and live for yourself :).

sometimes rejection hurts.... but 3 years is a bit long. At this point you will have to retrain your mind to stop thinking about him. If you see him or her daily, MAKE yourself look the other way with no double takes. If he pops in your head, stop what you are doing and change it up, call a friend, jump on here and answer questions, anything to occupy your mind. Don't get bored, don't give yourself too much time to think... stay busy. DECIDE you will get over him, don't wait for him to come back. If he does come back good... if not, don't hang on for nothing. harsh I know, but truth.