Keep trying for another 5-10 years. You'll win her over if you try hard enough.

You know, sometimes personalities just don’t mesh. Or an attraction can be one-sided. Do NOT let it make you get down on yourself, and do NOT resent her for it. It’s great that you’re nice and kind it sounds like, so please don’t let this experience make you change that. There are other elements that go into a relationship - Senses of humor aligning, hygiene, shared interests/hobbies, the right balance of listening and talking, etc. Even the way someone treats other people, or talks about themselves a lot, or does something normal that the other person just finds annoying - anything can have an impact and just be a turnoff. There are SO many factors that go into “clicking” with a person, and it’s not just about being nice. I’d say this is a great opportunity to use this experience to look at yourself and consider ways you can become an even better person. And keep in mind moving forward that interest has to be two-sided. There will be girls you like who just won’t be interested, just like there will be girls who will like you, and you just won’t be attracted to them. And no one has an obligation to anyone else - even if they’re nice. A lot of “nice guys” get upset when they strike out, and they begin to resent women, but it’s important to know that we ALL strike out sometimes until we either grow and change, or we just find the right person whose personality works with ours. And you will, too! I’m really sorry you got this huge letdown after putting in so much effort - I know it really, really sucks - but I love that you worked so hard and did your best. Keep at it, don’t let yourself get jaded, and you will eventually find an amazing girl who is just right for you - and you’ll also be just right for her :)