I know the philosophy, I understand the concepts, and I get the idea. But I can't do it. My mind won't let me.

I'm in college as a freshman. I'm surrounded by beautiful girls all day long and have every opportunity in the world to talk to them. Shit, I'm looking at one now sitting all by herself. I could easily walk up to her and just say "Hi". But I can't. I don't know why. I've read so much on here and outside of this site, I've watched videos, etc. I could create situations in my head that end perfectly with me acting natural and being myself. But when the opportunity presents itself, I lose all confidence and turn into an overthinking loser.

I'm at the point where I'm ready to give up and stop trying. I can't get into state. I've tried and tried, but it doesn't happen. I'm at a loss on what to do. I know I'm supposed to just act like I don't care, but it doesn't work that way. I do care. I just don't know what to do at this point.

Any advice? Has anyone felt like this before?