If you have severe back pain on one side it can be a sign of shingles. Have you ever had chicken pox?
Sounds mechanical, I would suggest seeing a Physical Therapist/Massage Therapist and/or Chiropractor. If that does not help then go to your GP/PCP. Does not sound like MS at all.
Jon
this has been going on for the last 3 weeks. and by the way am also forced to sleep on specific positions coz it can be painful trying to sleep on my right hand side.
Not sure, doesn't sound serious. I would suspect some kind of nerve impingment or pulling. How long has it been going on?