If you’re nice, Auto, be nice, and stop advertising and demanding things in return for being nice. If you’re being a Nice Guy to get girls, that’s not actually kind, considerate, or any of the other things that are synonymous with “nice.” If you’re actually a nice person, just do that and have a some confidence that that’s worthwhile on its own terms, because it is.
Short advice: be funny. It Works. Being funny requires listening, which is always good, but it also requires you to have an opinion of your own and requires that you not take things too seriously, which are also good and you seem to be having a problem there.
I’ve been through some forms of what you’re going through. Here’s the thing: you haven’t been all that unsuccessful in relationships, really. But you’ve been looking for very serious relationships at an early age, and that doesn’t always work out. One reason is that people don’t always know what they want.
But if I had to give you one piece of advice, it’d be STOP COMPLAINING. I know everybody needs to vent, but women don’t like complainers, men don’t like complainers, nobody likes complainers. Self-pity is not attractive, so after you get that out of your system, do some work on yourself. Build up some confidence and develop your interests. “Being nice” isn’t an interest and you can’t have a lot of interesting conversations about it. My first memorable conversation with my girlfriend was about Ray Charles, and our first really long talk was about bad movies - and I did almost all the talking. Two years on, I know for a fact that this isn’t something she goes for. But she could see I really enjoyed it, and like somebody once said, “interested is interesting.” I used to think my interests were too geeky for women, and that’s partly true, but not always.
There are times I’ve made my happiness too dependent on other people, which is a bad idea for any number of reasons and it sounds like your basic problem. My girlfriend is very upfront about this, and it’s not always fun, but the thing is, she’s very perceptive and she’s right. When you take the approach of “I’m not happy unless you’re happy,” you’re putting a lot of pressure on the other person to be happy because she won’t want to be the cause of your misery. It’s not chivalrous, it’s a bad setup that puts all the pressure on the woman. That’s not a very manly way to handle things and most women like to see more assertiveness than that.