I think it's a good thing your PT is incorporating some weight/strenght training, as I do think it will help, in the long run.
Having said that though - I'm sorry to hear that your back is giving you so much trouble! I am not sure what to suggest, other than the idea that when something changes (back injury), you can change too and sort of 'flex' along with the situation. If it turns out you can't do some of the things you used do pre-injury, then it may be that you end up trying something new.
Sounds like a fairly tough schedule (4 x 10's), but maybe later on, after the PT has improved things as much as possible, you might want to consider something like swimming or perhaps ask the PT's opinion on an upright or recumbent bike for home use.
As for NAS - you can leave it up in the air, and if you decide to go, just go and poke around. Enjoy yourself - without pressure to get clothes necessarily, or get something that will work now and in the future. Speaking personally - pants, skirts and tailored shirts are the first things that "don't fit" when the scale fluctuates. It takes a long time for outerwear to become too small or too big, and certain dresses can really go the distance. I have some slouchy-ish, looser fitting blouses and these work well at a smaller size *and* my currently plumper-than-I'd-like size. I'm happy that these types of blouses are 'on-trend'.
Hang in there, and here's hoping things turn around - I'm sure you'll find something *else* to do in terms of fitness/exercise - something that doesn't stress your back or cause pain to flare up.
