Just try and take deep breaths and focus on something else. If you keep focusing on the sweaty palms, etc it is only going to escalate.
Also try writing in a journal. Sometimes getting those feelings out does help.
Good Luck.....
I can totally relate! My hands also get real sweaty, I can't sit still an I have a horrible feeling overcome me. The only thing that seems to help me is breathing deeply an trying to stay calm. Probably not the best advice but I hope it helps some :)