You are attracted to this fellow, and it's probably painfully obvious to everyone. You say that you have informed him about your feelings (although you suspected he was in a relationship). His lack of action is your answer, unfortunately. Don't keep asking him or beat yourself up because he doesn't return your attraction. You cannot make someone love you or force romantic feelings where there are none. You've toyed with the idea of emotionally moving on, and now is the time to do it. Nearly everyone has been in your situation (or will be) so there's no shame in experiencing one-sided love. Just don't let this drag on too long.
Your best hope for getting him out of your system is this recipe: time, distance and distraction. When you have to be in the same settings as him (e.g., a classroom or work setting), try to select a seat or workgroup that is distant and sit out of earshot from him. When you can, try to choose settings where he won't be. Don't bring him up in conversation or respond to a lot of discussion with friends involving him. Tell your friends you're trying to move on from this crush so they can assist you. Look for other guys to connect with instead. Work on making yourself the happiest, most interesting and personally fulfilled individual you can; this positive energy attracts likeminded others. Five to 10 years from now, you won't remember much about why this guy was so special. Believe me.
Don't get stuck in the desperate pattern of chasing after someone who just isn't into you. After a while, other guys who may potentially be interested in you won't look your way because they'll know you only have eyes for your crush who doesn't like you back. Reframe what you want as something broader. You don't want this particular guy but instead a boyfriend with similar interests who will cherish and respect you and return your attraction. Good luck finding someone who is more suited to what you really seek.