I am new to this board, but have been swinging for a while. I have had some bad experiences with people. Don't go into this thinking you wont. But the good ones so outweigh the bad ones!! I can't tell you how right everyone is about the attitude...feel sexy and you are sexy! Dress in whatever you feel good in. You don't have to dress any certain way to be accepted. If you want something a little shorter or tighter, try Torrid. I know they have a website and are in a lot of malls. It's all plus size, though a lot of it is kind of dark and goth-like. A lot of cute stuff though too! Other than that, I always search the web for "Plus Size Club Wear" and come up with a lot of options.
Good luck!