Maybe your just not ready for a relationship then? Its not something everyone can just drift into. If your not ready to give a girl who your not interested in attention then maybe you just dont really want one right now? I know this can be a bit of a cop out answer but relationships dont just solve lonliness and other problems, they bring more problems too. And when people try to fill in gaps in their life with someone else it can have bad results.
Other than that, sorry anon I dont really know. Its not something a post online could fix I guess. I would suggest just trying to remind yourself of their good sides too. Someones bad side doesnt nullify their good. And sometimes its the flaws in people that make others compatible. For example, I was in a relationship with an extremely social person who talked loads, and I was quiet who barely spoke at all. Both were flaws but together we kind of just worked. Flaws arent a bad thing, they bring people to the ground and can be a good thing. Think about your own flaws and try to reach perspective. like "she might not be x, but Im not y. but she is z".
About feeling like a fraud, theres nothing wrong with feigning a bit of feelings near the start, thats just making an effort, just a little push to see if the ball starts rolling. If it continues then just end it and continue looking. It does take time to see if feelings for someone take root though, keep that in mind.