I met an HB8 3 months ago and I think that she was into me. However, I screwed it up by not escalating and being much too defensive (I really need to work on this - this is my greatest weakness). Hell, we had at least 4 dates and I didn't even try to hold hands. I guess this got me into the friendzone with her - the vibes I recently got from her changed a little.
I didn't contact her for like 2 weeks and this week she contacted me and asked me if I could help her with some uni stuff (another proof that I'm friendzoned). I AFCed and told her I'm gonna help her. Later, I invited her to come to a party with me afterwards but she said she's already going somewhere else.
What's the best move now?
Should I tell her I can't help her because something else got in the way and then freeze her out again? I know I need to get out of the "nice guy" frame. I also know that by now there is a very very low chance that I'll hook up with her but at least I don't want to make my chances even worse.
I any event, I will look for other girls and practice become better at escalating.

If you want to get with this girl the best thing you can do is get away from her. If you're ever going to break this "nice guy" image it will only be possible after some distance. First impressions are hard to change, but after a while you can come back as a "new man". Jealousy will also help.

Short story, just ignore her for a couple of months. By then you will most likely find another girl and forget all about her anyway.

If you really want to get this girl. you need to freeze her out and make her come to you. and if she wants you as more than a friend then she will comeback