Can a shot of Cortizone make you gain 6lbs in a day? Maybe water weight? Please !

Can a shot of Cortizone make you gain 6lbs in a day? Maybe water weight? Please help!!!?

I had a bad allergic reaction to some shots the Dr. gave me (immuno therapy--allergy shots), and they stuck some cortizone, benadryl, and adrenalin in my arm. I was also allergic to the Benadryl. Where they stuck the needles my arm is still VERY swollen and sore. However, since this happened I have gained 6lbs. I am praying it is water weight. If it isn't, is it possible that one of these shots made me have this reaction?
What is the best way to lose the bloat by tomorrow? Its my sisters wedding, and I cant fit into the bride's maid dress! I am in complete and utter panic!

2 weeks ago
PS--- THIS ALL HAPPENED YESTERDAY! :(

Just don't eat anything with salt/sodium in it. Drink lots of water. Coffee if you aren't allergic to it. And rest as much as possible... sleep is when your body heals itself... the more sleep you get the more time your body has to get rid of the infection/allergic reaction. Good luck and feel better!