Where you suppose to get rehab after it? A nurse should of followed you up and lightly badgered you if it were important.
Weakness causes instability and can cause pain, but internal external rotations dont just fix everthing, there are tons of exercises for shoulder rehab.
At the moment I am doing physio for forward shoulder posture and overdeveloped traps.
I set my shoulder in place and do flexion, extension, abduction, adduction, internal and external rotations, aswell as another excercise for adduction where I squeeze a pillow and also rear delt flies with hands externally rotated which for some reason are really doing a number on my shoulder.
I think all these are working my coracobrachialis or pec minor along with rotator cuffs, and also retraining the CNS with old movements but in an adjusted shoulder position, I am actually surprised at how fast its working but its mentally exhausting, much harder than my routine and it looks a lot easier than it is.
I was told to do 1 set of 10-20 reps with a 6 second hold on each lift, 3 times a day but this is way too much for me and its cutting into my routine, I am getting twinges, adjustment pain and bad DOMS so I am cutting it down to 1 set twice a week, the weight I use is fairly heavy for the movements but I never do them to failure.
If you need shoulder rehab its one of those things that go beyond the scope of the internet and especially any forums, you need a proper physical examination and be prescribed a personalised routine.