Im full of sympathy–lonliness sucks like nothing else in the world. And moments of feeling like you are feeling now are normal and inevitable and, in some sense, probably healthy.
That said, you will never find happiness in a relationship until you have learned to be happy alone. It just won’t work, because if you are dependent upon another person for your happiness, it puts you too completely in their power, it puts too much pressure on them, for the two of you to ever be happy together. Do you want some girl to feel like she is trapped in a relationship with you because she knows you would be miserable without you? No, you want a girl who choses to be with you for selfish reasons, because she is crazy about you and likes to be with you.
When you are looking at a girl like she’s your chance for salvation and deliverance, she wants to run screaming–she dosne’t want to be another person’s salvation, she wants a lover, a partner, a friend.
Furthermore, a smart girl knows that the attitude you have now means that you arne’t interested in a girl for who she is, you’re interested in a girl for how she makes you feel–and that’s not flattering.
Lastly, it is especially not flattering when a guy is desperate because it suggests he’d settle for most anyone that would take him, which is pretty insulting to the girl he asks out, if you see what I mean.
Luckily, learning to be happy on your own and meeting chicks that want to date you can be accomplished i the same way–spend time doing social tihngs that you enjoy for their own sake. You like to read fantasy books? Join a bookclub, take a community college class on fantastic literature or creative writing, go to a roll-playing convention, strike up conversations with people you see reading books you like (though not just the cute, or even female, ones–experience striking up conversations with all sorts of people is important here).
Try to be someone you would want to date. This dosen’t mean you have to change yourself, but rather accept who you are, learn to like who you are, see what you have to offer awesome chicks.
And if you always–or even often–feel like you felt when you wrote the OP, go see your doctor ASAP. You sound depressed, and there are many different things that can really help with depression–but love isn’t one of them. Trust me on this.