Hrm.... I would suggest socializing a lot and getting out of your shell, to be honest. This can help you feel better about yourself, which in turn helps you get in touch with yourself, and recognize more of the mental aspects of romance and potential romantic partners.
As for how.... Just try to randomly strike up a conversation with someone who seems friendly now and again. If it doesn't work, try not to lose heart. Other people probably have better advice on how to be more social around here, but generally, it's a good idea to help feeling down, I think. As long as you make sure to find people you really share interests with somewhat, and whom are really friendly and not just users. It takes some serious thinking about other people's personalities and motives, which can be hard, but is worth it.
In the short term though, for the erstwhile, I suggest applying that last sentence of the above paragraph a lot. Even try to make a game from time to time of figuring out what other people will do when it doesn't really relate to you personally, to help you hone your skills at it.
....
Honestly, I'm not sure that was good advice, but as I figure it, giving bad advice is even better than bumping for giving a problem some attention. People will read it and go "oh no, that's completely wrong," and start thinking more about your problem. If what I said does make some sense to you, or people start agreeing with me on it, then I guess that's good too though.
[EDIT] Not to say the advice here is bad, but it was posted whilst I was writing up this post. lol
_________________
Semi-colons are awesome; you are awesome if you use them.
I enjoy random PMs. ^.^