I overdid the zinc a few years ago and gave myself a mild case of poisoning. Check this thread here.
It took a while, probably 2-3 months of oversupplementation, got worse as I tried to keep supplementing, and only cleared up once I quit supplementing everything with zinc in it for a few weeks. If you start feeling nauseous and get GI issues and get that feeling in your mouth where you're about to throw up all the time cut it out. I was getting that an a few other symptoms, don't quite remember now.