Rest and taking things easy is probably the only option at the moment, I managed to find an old office chair that supported my back as the chair could be tilted back, sat in that for months, still do actually, most comfy chair in the house.
I used one of those belts that's meant to build your stomach muscles up slendertone I think it's called, didn't do much for the waist line but it really did help with my back, pilates is good as well if you can find the right instructor, definitely worth looking in to, and loosing weight if you need to, all helps, all things for the future though. As you've had experience of this before you probably know all this already, but good luck with it, hope the worst of it passes quickly