Louise, I'm another one that is shocked that a rheumy and PT told you not to exercise. If nothing else, they should tell you why as there may be something going on that might be exacerbated by it. If it is that you are in pain, then you should know that exercise can relieve pain if you play it smart. While you are hanging off that noodle in the pool, kick your legs a bit.
Exercise keeps our joints lubricated, keeps our muscles from stiffening, helps keep our weight down, helps us sleep better thus relieve our fatigue, and also helps relieve the depression that often goes hand in hand with chronic pain.
But don't push it. Just do one minute at a time if that's all you can handle right now, and build up to 15 minutes at a time. Start where you are now, not where you wish you were. If you're in a ton of pain, take is slowly and make it small. A little is enough. But move those bones!!
And find out from the PT what the concern is about you exercising. As I said, there may be something going on that we know nothing about.
Hugs,
