Why am I repulsive? How can I stop caring about being alone all

File: Christ_in_the_Wilderness_-_Ivan_Kramskoy_-_Google_Cultural_Institute.jpg (109KB, 800x701px) Image search: [Google]

109KB, 800x701px

I don't know what it is about me, but for some reason people seem to not want anything to do with me. I try to be friendly and approachable, I tell jokes, and I try my best to listen to people when they speak. But, for some reason, every time I try to be friends with someone, or show some interest in them (romantically or otherwise) they seem to hit this wall that just makes them shut off any interest that they may have had in me. I use to be a very introverted, quite guy -still am to a degree-, and so I've worked on changing that. I've started exercising and have managed to lose a considerable amount of weight. I have a hobby that I am very passionate about, but none of that seems to matter. I'm always the outsider, the other. I'm in a constant fight to develop relationships. And I've had no luck. I still feel the pain of this I guess because I am still young (24), but it hurts like hell. Especially when you reach out to someone who professes to care about people depression and the suicidal.
The worst part is that I think that when I try and fail, I become desperate. This desperation then pushes people away even more.

How can I stop caring about being alone all of the time?