Maybe try wearing a lightweight backpack and see if that helps. I know that somebody makes one especially for quilters but can't remember who... google might be a help there.
When I went on vacation I wore a backpack purse and was so surprised that my back held up so well with that. Also, make yourself a ziplock rice bag and lay it on your tummy when you're in bed on your back. That's a trick I learned from a pain class... and it really works! Strengthens your inner core effortlessly.... You can add or take away rice to make it comfortable, and adjust it as your muscles get stronger. Hope you try this, because it has worked for me and some others in that class. Blessings on you!