If he values his job, he wouldn't dream of dating a student I'd say.
Like you said, it's a crush and it may pass (ok, it hasn't in two years). I'd say you do whatever you've done for the last two years to cope with it until the end of your course. If you still like him afterwards, ask him when you graduate. I don't know how close you are; if he knows your name or whatever, if he does you could ask for his number/email when you leave so you can "stay in touch", or just be bold and come out with it, doubt you'll see him again so you have little to lose!