Well, before you didn't do things because your parents didn't allow you to. Now, it's only you that is holding yourself back.

You already have some hints that others liked you in school, so it isn't like you are proving anything to them, its all about proving something to yourself really, right?

When we are young like that we "self judge" alot and often think others see us the way we see ourselves. But if you were a pleasant person and validated others with your kindness, that is all they will remember about you, which is coming out in FB posts to you.

Going may bring you some closure, because you get a chance this time to make your own choice and "just go be with old friends". They just want to see you and how you made out, which you made out fine, are fine now, that is all that matters, you outgrew whatever challenged you in your past.