I feel for you, man. When I was younger and inexperienced, I thought of dating as a simple video game where you accumulated points.
You get more points for agreeing with a girl.
You get points for acting bland and inoffensive.
You get points for buying gifts and giving compliments.
You get points for being good-looking.
You get points for having money.
Then, after a certain magical threshold, you’d get to cash in those points for something you wanted with a girl: a kiss, sex, a relationship, etc.
Note that in this conception of things, women were just passive, vapid, simple-minded automata.
I was lucky enough to find a girl who liked me in spite of all that. Thanks to her, I was able to learn more about dating. Thanks to her I learned about sex. Thanks to her I started learning that women were, shockingly, people!
My apprenticeship in matters of love and relationships came late—I was 21—but it did come. I know people for whom it never comes. They are well into their 30s, still wondering how some guys, whom they view as inferior to themselves (less educated, less nice, and with worse employment prospects) are able to have relationships and sex while they themselves can’t. Like men in pre-scientific societies inventing a pantheon of deities in order to make sense of a complex world, these men afflicted with nice-guy syndrome try to find simple answers to their questions:
it must be that women like superficial things.
it must be that women like the bad-guy image.
it must be that women don’t know what’s good for them.
it must be that women are stupid.
Not only do these men become misogynistic over time, but their behavior becomes very robotic:
Insert compliment now.
Insert bland joke now.
Initiate appropriate physical contact.
It’s hard for me to say what exactly you are doing wrong, since I haven’t observed you and I don’t want to make assumptions about you. My advice would be to talk to a female friend of yours and see if she can give you individualized advice.