Car accident caused a herniated disc in my spine. How much compensation should I ask for?

I was involved in a car accident about a month ago. Someone hit me from the behind. I went to the ER immediately and the doctor the following day. I'm still in pain and seeing a chiropractor on a weekly basis. The results on the MRI show that I have slight herniation on c4 and c5 discs pinching the nerve. How much should I ask for from the guy's insurance besides the medical bills? I really don't want to hire an attorney. I just want to settle but don't know how much to ask for pain and suffering...