Angst is basically an (typically teenage) extreme emotional reaction that is far out of proportion to the actual problem (If indeed any problem actually exists).
One of the best examples here might be spots. Most teenagers get spots, and to an adult it's not a big deal - but in terms of teenage angst: "My spots have made me so ugly that no boy/girl will ever look at me again! I am a loathsome creature whose very gaze should crack mirrors and cause grown men to cry out in horror! Surely there has never been a wo/man as ugly as I!"
That's angst, in a nutshell <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />