What Is The Treatment For Spinal Fusion In The L-4 Area?

Hi, I had a spinal fusion in the L-4 area 7 weeks ago..have had severe pain then get better. If I try to get out for an hour I have severe back and leg nerve damage pain. I drove 4 hours and over did things. That night I wet the bed which freaked me out. I've never done this ! What caused that ? Also...My tailbone feels like it is broken when I sit or get up to walk. Help ?