I'm 23 weeks and today the back pain while sitting at my desk at work is almost unbearable. I have a pillow, they ordered me a new, very comfortable desk chair, I'm getting up and walking, but nothing is helping. Getting up helps temporarily but within a few minutes of sitting, it's awful again. I cannot fathom 17 more weeks of this, and what I imagine will be increasingly worse pain.

What did you do to ease pregnancy back pain in similar situations?