siempre nada, I am so sorry you had this awful experience!! You know, I know you see it as a "new low" but crying in disneyland is not that strange, I can bet ANYONE in your situation would have been devastated - your band 'mates' abandoned you, nobody brought you into their group and even the parents ignored you. I would say it's a low for THEM, to behave in such a disgusting way to another human being, another member of THEIR group. I feel sorry for them, siempre nada, because not one of them had the guts to be kind to you, somebody who was obviously lonely and struggling. What does that say about them, that they can see you upset and they carry on? Maybe some of them wanted to come and talk to you but were too shy or worried you how you would react, I don't know.
You did say you isolate yourself, but if somebody invited you with them on a ride or to eat lunch together or something, would you accept?
Maybe if you opened up a little more people would really like you and want to be around you..?
I agree with Mike, though, having no friends right now is not an indication that you won't ever have any, it's very unlikely that this situation will carry on. I know people in school who were "unpopular" and now have lots of friends. I think the older we get, and the more people we meet, the more open minded we are. You will eventually meet people who will suit you and you can have a group of friends with similar interests etc.

Again I'm very sorry you had such a horrible time. Your band mates and the parents let you down, big time. I can't believe no parent tried to involve you.
I'm sorry you didn't feel able to tell your parents about it, but I think maybe it would help you to share it with them, to let them be there for you, it might help.

Hope you are feeling a little better at least x