I highly recommend trying out a massage.. just make sure that they know you are pregnant! Helps out a lot :)
I had really bad sciatica pain with my first. He was posteria (back to back) so every time he stretched he would put pressure on my nerves and often times I would just collapse mid step. Best thing I found for sleeping is the body pillows or a U pillow. If you don't have one then normal pillows work as well. Put one between your knees when on your side, also one under you bump. On your back place one under your knees and one under your pelvis. Also a warm wheat pack or a something similar on the effected area helps.
Good luck ladies xx
Bump* I wanna know too!! I have been having the same problem and I'm 33+5