ONe night i took about six hits off a joint and have never been so high in my life because i was around people i didnt know and wasn't comfortable with. the situation has a lot to do with it just make sure you feel safe and secure when you smoke b/c i know a lot about getting paranoid. Speaking of paranoia that is probaley what you experienced. YOu were really high but your brain was telling you that something was going wrong and therefore you had a panic attack it has happened to me once on weed and i wasn't even that high