Just remembering being on Rebif makes me shudder. I was constantly achey and sick. I tried talking to the MS Lifelines nurse, and heard the same thing you did. After nearly a year of this, My neuro said to stop taking it for a couple weeks. I did, and felt SO much better.
You're not doing anything wrong, Renee..It may very well be that you cannot tolerate the interferons. You'll know in no time if it's the Rebif that's making you feel so bad.