I was given this shot by an idiot of a Dr who told me that it was...

I was given this shot by an idiot of a Dr who told me that it was "for inflammation". He never told me it was a steroid and even though I asked repeatedly about side effects, I was brushed off with "if you don't have a reaction within 15 minutes, I would not have any". I wish I had trusted my gut instinct and never let him do it. I have only been on it a week so it hasn't dented YET, but I have mood swings, irritability, insomnia, jitteriness, dry mouth, racing heartbeat, and though I am eating only 1200 calories a day, I am already gaining weight. Does anybody know if there is a way to get this out of your system faster? I had a hysterectomy so I do not have the bleeding issues.