Post op

I recently had my band a week ago.  I assumed that I would be ok enough to go back to work by now but I'm not. I'm ok but the question I have is has anyone had a problem with their back tiring them out? I can't stand to shower long enough. I want to sit down after a few minutes. I cannot walk up my steps without my heart racing by the time I get to the top. My doctor says that it's the gas. The only thing comfortable is lying or sitting. Other than the back pain and the tiredness, I'm okay. Has anyone else experienced this? Please help.