Severe backache! Help!

I am 29 weeks pregnant and have had back pain on my right sides r the past 2 months now and it just seems to be getting worse. I can't sleep. I sit all day for work and it affects my work because I'm in so much pain. Even laying down doesn't help sometimes! I have tried heating pads which don't do anything, icy hot, warm baths etc. Anyone else have pain like this and what's you do that helps?