kelju, man. that sucks ass, dude.
i hurt my left shoulder back in september of last year. i too didn't have enough to get an MRI done, but my GP and PT both said it was rotator cuff related, most likely rotator stress. i hurt it doing military DB presses. when my left shoulder gave out the 35lb Db came down, taking my shoulder with it at an almost 45-degree angle in the wrong direction. it was accompanied by all kinds of popping and tearing noises. i thought i had dislocated my shoulder until my shoulder naturally rotated back into the socket. to this day i'm still very nervous to pick up the dbs and hold them anything above an arm curl.
anyway, my doctors strongly suggested that i be icing it at least once a day and even take ibuprofen or something to reduce the inflammation.
i was given a band and started doing rehab exercises every night, slowly building up to heavier gauge bands. look up that website that premier told you about. i could even look at it and tell you which ones i did if you want. some of them i could tell were helping and others i could tell were just 1 or 2 reps away from hurting it worse, so be careful when you're trying them out. your ligaments are very weak now.
i took about a month off from lifting and tried some stuff in november. re-injured my rotator cuff and took a solid 3 months off. i've been back at the gym for about a month or so now and just now started adding shoulder stuff back into my routine. the baby weights, mind you.
i don't want to bring you down, but i hope you can learn from my mistake of wanting to rush back into things too quickly. also i hope you see that people can and do recover from it! it's a slow, long process. but ice your shoulder, do the rehab exercises, and you'll start rebuilding your rotator cuff's strength.
i know how discouraging it is. hang in there man.
-a fellow recovering rotator cuff injury victim