Returning from shoulder injury

About four months ago while doing an open water competition I started noticing a little discomfort in my right should while swimming crawl. I took about a week off of training and then worked back up to my 5K. I then swam the Corsiquana (sp?) Cup 5K and got beat up pretty badly by the surf, did not finish, and had more shoulder pain. Took another week off, iced, and so on. Went back in and swam the Pan Am open water 5K and had major issues, finished but not pretty. Shoulder pain got worse. Then, because it was paid for already, flew up to the Northeast and swam another event. I have not swam for about a month and a half until Friday (yesterday). I talked with my doctor about it and he wasn't that concerned about it, said rest it and give it time. I should also say that I am not able to take NSAID's for pain and stuff. I did a 400M warm-up (long course), then did a slow set of 8 x 50 crawl then 8 x 50 *** (my stroke of choice), and then for the hell of it did 2 x 50 back, and 1 x 50 fly, and then 200M warm down. See, I was trying to be a good boy and not kill myself easing back in (I'm not a good liar, someone started back-washing the filters and once I could no longer see the lines I gave up). Shoulder pain is back in my right shoulder, not severe, but a dull aching anytime I rotate the arm (or when my dogs pull the leash hard that I hold in that hand). As I was swimming I noticed I do not have problems with the breaststroke, but the crawl and backstroke hurt. Couldn't really tell on the fly as I suck at that stroke and am more worried about not drowning than being in pain. Suggestions? Anyone ever do all breaststroke workouts while recovering from an injury? Am I nuts to even think about trying? Thanks!