Rotator Cuff inflammation

I took a look through the archives and saw that quite a few of you have had some gory shoulder injuries :) Mine is probably very minor by comparison, but I know from experience how debilitating chronic injuries can become, so I hope I've caught this early enough. I only started swimming front crawl in October '12. In the last month or so, I've weaned myself off the pull buoy completely and I feel that I'm applying more force from my shoulders. Also, I've caught myself swimming with my trunk a bit 'flatter' in the water, so I need to lift my arms a bit futher during recovery... which seems to take a little more effort on the part of my shoulders. As a countermeasure, I've been trying to force myself to rotate a bit more. Finally, I started taking back crawl lessons and it was when reaching overhead that I felt pain sharp enough to make me stop. Yesterday, I did loads of legwork with fins, *** stroke and hardly any front crawl at all. I thought that maintaining motion and stimulating bloodflow around injured areas with gentle movement, but minimal loading, would do the trick. Last night, on leaving the house for my evening walk with the dog, the little fellow saw a cat and made a lunge... His leash, which was held in my left hand, delivered an interesting jolt to my shoulder. What would normally have been easily absorbed, left me in sharp pain. I now have a constant dull ache, so I visited the doctor today and he's given me anti-inflammatories (Ibuprofen with Arginine) and muscle relaxants to make the shoulder muscles slacken off at bed time. I understand that I need to rest, but I don't want to let my shoulders atrophy over the coming weeks. I read online that as long as it's not painful, some light *** stroke as well as finning with arms by the side is OK. Does anyone have any advice on the subject? Many thanks in advance.