Sad about this guy that I can't get over :'(?

Have a uber crush on this "straight" guy. To cut it short I have decided to get over him but its too hard since he lives across the street from me. Everytime I see him I feel like throwing up and get nervous and upset. Im upset cuz I like a guy thats a douche bag, pot head, drinker, and a player. I know its sad how can i like someone like this? The sad part about it is that he is my brothers friend and hangs with him a lot. I dont know what to do when I see him. He says hi but i dont want nothing to do with him no more. Should i completely ignore him even if he says hi to me? i want to pretend he is a ghost when he talks to me. So depress that i dont want to go out, im mad at everyone, and i dont want to do anything anymore!