Worried about hearing after going to a gig, any advice?

Typically if the soreness/muted hearing went away quickly, the damage wasn't permanent. Usually, only repeated exposure causes permanent hearing damage. Unless your symptoms return or worsen, I wouldn't worry about it. Your ears will tell you if there is something wrong by a muted sound, a tinning sound, or ringing. if these symptoms have subsided, you should be in the clear.