Unhealthy Love? Advice Needed.?

I'm in-love with a guy who doesn't know I like him. He doesn't like me, anymore (he used to have a crush on me a long time ago). There is no hope for a relationship at all.But I still love him and can't get over him. It's like I'm content with knowing that I love him and I can't move on from it, even though I know he doesn't feel the same. It hurts because he flirts with one of my friends a lot, but if he wants her, I'm good with it. It just doesn't stop the pain.I gave up a really good guy for him too, I thought we had a chance, long story. Now I'm alone and seemly in-love with him forever, no matter what he does.Give me advice please.

just set yourself free....feel free to flirt with other guys, and put on exra make up, and just be beautiful! and if you can, get a bf. but you'll get over this guy eventually. time with solve everything! good luck!