I know it's easier said than done, but having been in the same situation myself, the best advice is not to worry too much about it.
I met my husband on MySpace (I was really shy, hermit-like and didn't get out much), and it was really just pure, dumb luck. The first three times we met I was so shy I wouldn't even look him in the face!
Thing is, when I met him I was about 200lbs and he still ended up loving me. He's not a "big" guy at all, and we've been married for about two years now.
There were phases I went through of self-loathing and being emotionally closed-off, and other times I just didn't give a darn.
I know it's really cliche, but you'll meet someone when the time comes. I had actively tried to find a guy in the past before I met DH, with online sites and going on dates, but right before I met him, I had given up. I NEVER expected to meet a guy on MySpace! Sometimes, it just HAPPENS. Putting yourself out there always helps, though. If not for actually finding someone, but for the experience of just getting out and developing your comfort and social skills.
I agree with the other poster about finding someone through activities, but I know that's easier said than done. I was always too shy to go and join something by myself.. Maybe if you have some female friends you could join up together? Things like Habitat for Humanity are great.. Also, probably singles events with your church/temple, etc. also as previously mentioned. There are also business networking events like the Young Professionals societies in some major cities like "Philadelphia Young Professional Society", etc.
I wish you luck, and the point I guess I was trying to make is that you WILL find someone great who loves and appreciates you, and oftentimes when you aren't even looking for it. There really is someone for everyone.. Just look at 400lb women who are happily married, or people with physical disabilities, etc. There will always be people who can see past whatever you THINK is wrong with you. It's definitely not impossible.
Wishing you lots of good karma in the mean-time!