There doesn't seem to be that much serious advice on here, but I will take a shot at it as I have had several friends with similar problems.
My first bit of advice is not to dwell on finding a girl. Don't fall for girls. Get on with your life, and girls will fall for you. You may describe yourself as a "hopeless romantic" or something like that...just forget about it and focus on other things.
So many times I have had friends who are like I am not rich enough, I am not good looking enough, I am not good at anything...why would a girl like me...that is why all the ones I fall for don't like me. It is not the money, the looks, your shape, or that you aren't good at anything...it is that you think that. Girls are all about confidence. This is a concept that is easy to say and not so easy to do. This is why girls are attracted to "bad boys" all the time. Usually bad boys come off as confident (even if the only reason is that they don't open up). Girls swear they want a guy who is sensitive, but actually, they don't in a way. They want the guy to be sensitive when the time is right, but otherwise they seem to want the guy to be strong and unwavering. A lot of times, guys I have met who have never had a real girlfriend are always saying how they are so nice and so sensitive...that is most likely their problem...you can be sensitive, just don't be so mushy...save that sensitivity for special moments (this doesnt mean to be an @ss...just don't be overly...yes yes yes).
Now the best way to gain confidence is to make some money, to get in shape, or get talented at something. These are the things that make guys confident.... and this is why girls are attracted to guys who have these attributes. It may seem superficial, but actually, it is your confidence that they are all about. Focus on those things...go back to school if you want to get a better job, join a gym...start playing a sport or pick up a hobby that you know you can get good at. When your start focusing on other things, the girls seem to just start lining up. It is the mr. sensitive who is constantly looking for girls that never seems to find them.
Now my whole theory on girls above is very general...there are always girls who are not usual and like guys for different reasons. I am just giving you general advice...you can't get them all.
Now I have another buddy who takes a different approach, although kind of similar. His is a little less refined and not so popular with the ladies. His also requires a lot less effort than my advice...so probably not all that good...no pain..no gain. He feels that when you are in a slump with girls and you don't feel like you are aiming too high, then you need to do a slump buster or two. Basically, a slump buster involves aiming your sites really low...basically a sure thing. Once you have had a little side "romance" with one or two of these slump buster girls, you will start to get your confidence back. It might even take a bunch of these slump busters. Eventually though, you will be confident enough to go for the girls that you want. Weaknesses I see with this plan. First, you have to be an @ss not to care for the feelings of the "slump busters". Second, you could be taking the chance that you are too nice a guy and will get stuck with one of these "slump busters"...that is never a good relationship. Thirdly there are things like STD's and pregnancy to worry about. So I really don't recommend this approach to you...but whatever floats your boat.
Just remember confidence. Hope this helped...
Later