Baby #2 was worlds worse compared to baby #1 as far as sciatic pain...and it started really early and got continually worse. I saw a PT and while most everything he did was only a temporary help, we finally found something that helped...a belt/positioner that helped keep my hip stable so it wouldn't rub my iliac nerve. I can't comment about the meds, not having taken any. Hope your PT can help!
I had sciatic nerve pain constantly for many months & I went to my chiropractor on a regular basis which was a miracle for me. I still go to him & I'm 35 weeks. One position that brought me comfort was to lean over a table & put my elbows on the table & gently lean forward to stretch the hamstrings. Leaning forward over something helps move baby away from the nerves for a bit. Also laying on an ice pack for 30 min brought much relief.
Good luck. I know exactly what you're going through. Hang in there!