Back pain is the suck. Mine was acting up too until a few years ago when I started doing hot yoga (like normal yoga but in really high temperatures so you sweat like a pig but it's really good for your muscles and you feel awesome afterwards) and that totally took care of it. I don't know if that's something that might appeal to you, but it's a very different atmosphere from the gym (which I hate too!) and is also a great stress reliever.
Otherwise, I hope you find something that works for you and that you can do at home. We'll be cheering all the way!