Pregnancy pain and old injury

I am really having problems with Sciatica pain right now. I originally was injured in 2003 while training for the Marine Corps at Officer Candidate's School. I had fallen off of the obstacle course & landed on my butt. Two days later I could barely run...it was horrible. I was discharged & sent home & given disability and received 6 months of Physical Therapy. I had a lot of problems, though, with the military & getting the doctor's bills paid. I eventually ended up paying for a few things myself & not renewing my benefits because I was just too fed up. Unfortunately, the pain never truly went away. I felt it while trekking across campus, when I tried to go out dancing or any other physical activity I participated in. I eventually just started doing less and less physical activity with the result of gaining about 30lbs. Now, though, being pregnant, I only need to walk or even just sit & the pain cuts like a knife! A nice slow song came on the radio the other day & Mike & I spontaneously started dancing to it, but I had to stop because it hurt so bad. How am I supposed to get through our wedding and honeymoon with it like this? I had asked my Dr. if there was some kind of anti-inflammatory or something that I could take since that's what I had been given before, but she just said "No, just Tylenol". It just sucks!