What are the side effects of amitriptilyn?

I have been in tx since Nov 2010 for Hep C and 3 weeks ago the Dr prescribed 50 mg amitriptilyn. I take them about 6 to 7 in the evening. I feel the effects some 15 to 18 hours later. I feel numb from head to toe and shaky inside. I feel like I am flying. I also get muscle and joints twitches when I try to relax and go to sleep. Is this all normal??