What can I do about my back?

I’ve always been a hard worker. I could do yard work, lifting and hauling for hours.

Now, however, if I spend any time bending and standing my back just ends up hurting so badly that I can barely walk. I pulled out and rearranged some bricks around a planter, and cleaned stuff out from the plants. This meant I was on my knees or all fours for 30 minutes. Then I went to push a grass seed spreader around the yard…and I couldn’t do it. By the time I got to the front yard, I didn’t think I was going to be able to make it back to the back door.

Around Easter I picked up loads of branches and threw them over the fence, then picked them up and carried them to the trailer to be hauled away.
The next day I couldn’t help the kids color eggs unless I was sitting down. I couldn’t bend over to pick things up.

Any idea how to fix this?