The headaches got so bad for me, that I had to stop. If you're reacting with hives, away from the injection site, you are probably allergic. I'd seriously stop taking it, and try to get a prescription for prednisone to help with the reaction.
I would call your Shared Solutions nurse. They will give you the best information.
You can take tomorrow's show wishin 12 hours of the next shot. Wait, talk to Shared Solutions and follow their recommendations.