Most Helpful Guy
It can be hard but the best thing to do is try to move on. Obviously if you work with him then it's more difficult to cut him out of your life... but as someone with experience in this area, you'll just be stranded in a sea of hope and life will pass you by. It's hard but acceptance that you can't be with him is the first step. After that, it gets easier
Most Helpful Girl
For me, all crushes eventually fade. Even the ones where in the moment I think "I'll never get over this" - I always do. But consciously trying to forget those feelings.
But maybe it was easier for me because I wasn't rejected. I decided these people who I liked weren't good for me due their maturity or the people they hanged around with so I justified not thinking about them by focusing on their negative attributes. That helps a whole lot.