I've had social issues pretty much my whole life but it goes in and out episodically, really and not really from a particular psychotic break.

I'm sure part of you exploded like that because all you were thinking the WHOLE night was how frustrated you were with yourself, and you're mulling around in your head... repeating to yourself how much you wish you could just be like everyone else and have a great time. (At least... that's what goes through MY head when I'm in that situation.) So when the guy asked you "why you weren't being social", you were only verbalizing what you'd been thinking for HOURS to yourself. (Again... that's how it would have been if it would have been me.) Also, I'm really bad around new people too, even if I AM in a social mood. I can sympathize completely.

I wish I had an answer for you on how to be more social. If I knew I would most certainly tell you. But if I'm in that state I personally withdraw from everything until the feeling goes away because I really don't know how to force myself to be social. Sometimes I can fake my way through. At least to pretend to laugh when everyone else laughs. I'm also "lucky" that I have a nervous smile, so if I'm in an uncomfortable situation I'll smile or laugh even.

I'm sorry that you're having a hard time with it. I'm sure it's a million times worse since it's coming after a psychotic break.