Well, at least you tried. I've had two serious unrequited loves or whatever in my life, one my friend (without my permission) told her I liked her, and I tried asking her out. I failed. But that was significantly easier than this other girl I knew, who honestly was light years better than this other girl, I didn't try. I was too scared, and she had a boyfriend, and I thought logically I couldn't handle a relationship with my life being so out of order, I figured I wouldn't benefit her by dating her. She got married. I thought I'd be fine, but I was pretty devastated. So at least you tried. There's closure. You trusted your feelings and intuition and whatever enough to try. So congratulate yourself for that. It's infinitely worse not trying, as then your "what if" questions have more of a logical basis.
As for what to do with the rest of your life, hell if I know. Good luck I guess.