If you are crushing on someone just tell them. You got nothing to lose. Look at this way, are you with them now? No. If you tell them could you? Yes. And if they don't feel the same, at least you know where you stand and you're still in the same place not being with them. But again, at least you got it out and know where you stand;))
My longest crush lasted for three years and the thing is you never quite fully get over that person. However, keeping yourself busy and avoiding that person helps in the process of getting over your crush.