There is a girl I have liked since high school. In high school, I told her I liked her a few times. (I think 3 times, probably doesn't help) She once said she could never love me, so I moved on. Then I realized I couldn't move on and I still liked her. It's confusing, because she will still invite me to hang out and have fun with friends. SO my question is, why would she want to be my friend after such events, and does inviting me mean she has even the slightest feeling for me?

She wants to be friends with you but it sounds like she has no romantic interest in you.

She has no feelings for you, move on.

Hanging out with a group of friends doesn't mean she has romantic interest in you.

Move on.

You got to learn that being friends and being romantic with someone is a very very different ball game.
My advice is to cut off contact with her because you being around her just sounds very painful you need time to heal and focus on moving on bud or you will be stuck on her for a long time!

A hang out buddy is hardly a romance so forget it. Never say you can't move on because you can if you accept that her feelings are not the same as yours, and will never be.

Say you don't want to, that's accurate, but doesn't change the simple FACT that you have too. YOU HAVE NO CHOICE but to move on!