Sciatic pain during pregnancy

Recently I've started getting an absolutely debilitating sciatica nerve pain. I'm just about 17 weeks and I'm almost in tears trying to work during the day plus it keeps me awake at night. I can't imagine trying to do the whole pregnancy with this, it feels like ill end up on medical leave. I've heard a few different ideas of what might help. Has anyone tried these? Which one worked for you? Any other suggestions? I'll try anything!

P.S. yes I have done stretching and yoga and it only gives relief while I'm in the stretch but the pain comes right back, I need better relief than that.