@Radical: I've experienced AP firsthand, but to my knowledge you and I have never met except in a purely virtual sense. So if AP is a delusion, I'd be compelled to classify you as a delusion as well, since I have more direct experience of AP than of you. All I have from either of you is the info that comes through my senses.
How would you go about proving to my satisfaction that you actually exist? And how would that be different from my AP experiences?
To me the astral world is just as real as -- and no less valid than -- the physical universe. If one is a delusion, I'm inclined to classify the other as such too. My personal opinion is that all these different worlds are just projections of thought, so technically they're all delusions. People in the physical world have their opinions about the astral world, and astral entities have their opinions about the physical world. I've never met a being on either side who had all the answers. Astral entities have a different perspective on the universe than we do, but they certainly aren't omniscient.
Amusingly there are astral entities who don't believe the physical universe really exists, since they've never been here. So you may find it comforting to know there are beings in this universe who don't believe in you either.
It's perfectly OK not to believe in the existence of astral worlds -- to be honest I wouldn't encourage you change your beliefs in this area, at least not unless you know an experienced AP'er who can coach you. It's not the sort of thing you're likely to believe until you go there personally, and it won't hurt you not to believe in it. Rest assured you'll have plenty of time to explore the astral realms once you no longer have a physical body to worry about, so there's certainly no rush.