Are you reading my mind? Because really, this is exactly what I'm thinking every single time I see a girl. I couldn't agree with you more, man... I have the exact same problem. I wish I could help you, but I don't have any answers either. It's just like you said... you look around and every girl you see is going out with some asshole that cares nothing for them, and meanwhile girls just keep talking about how they all want nice guys. I even posted a rant here about it a few days ago, and had like 25 girls denying that they do such a thing, even though you and I both know that nearly every girl we have ever met is like that. They don't want a nice guy... they want a completely platonic friendship with a really nice guy who they can come to and cry to and talk to and share all their worries and doubts and fears with, knowing that the nice guy will listen to them... but then they go for the musclebound idiot with no personality that cares nothing about them instead. And it never ends.
I'm with you on the relationships... that's all I want too, just an honest, hopefully long-lasting relationship. I don't want a fling, I don't want a one-night stand, I want a real relationship... and in my experience, regardless of what the ads say, girls don't want commitment. It's no longer the guys that are afraid of commitment, it's girls. And you know why? They're afraid of giving up their freedom. I know it sounds chauvinistic, but it seems to be true. They're free, they can have any guy they want, and it's not even socially unacceptable for them to sleep around anymore. They can get jobs, make a life for themselves, and do anything completely on their own... they no longer need men in their lives, beyond sex toys. Having a relationship means risking losing that for marriage, children, etc. So why would they even consider it?
And look around you on this site... there are tons of girls upset over not being able to find Mr. Right, upset that their boyfriend doesn't treat them well, or embarrasses them, or can't remember their birthday, or whatever it may be. Or they'll post pictures and want you to choose their next boyfriend based on looks. Disney has them brainwashed, my friend. Brainwashed to believe that they should not SETTLE for a nice guy. Why? Because Nice Guys are like the Quazimotos of the world... and if they just wait long enough, someday their Prince will come, riding up on a white horse, and they will live happily ever after with a fairy tale ending. So they don't settle for us, because they believe something better will be just around the corner, if they are just patient.
What's my solution? Give up. Having been through more rejections than I ever care to count, I can honestly tell you from the bottom of my being that I wish I had never attempted to have a relationship. Relationships have given me more heartache, more headaches, cost me more money, time, and resources, and made me hate life more than anything I have ever attempted to do in my entire life. You may think you want a relationship now... and you do. But I can tell you that going after a relationship right now, at your age, is THE biggest mistake you can make. Girls don't care, dude. they just don't care. And you would be wise not to waste your time on them.