Assuming that you have full movement & that you are gym ready (if not half everything for the first 4-6 weeks)
Let's focus on rebalancing the shoulder as a whole.
Starting with the rear delt as i think your front delt is stronger. Pulling the shoulder cuff too far forward. Hence the lack of stability.
Assuming a couple of things here, gym fit & access to weights too:
Day 1 - upper body work out
warm up - heavy bag boxing 5 mins (every seen a boxer with bad shoulders? or a shoulder injury? Didn't think so)
cable rows or one arm dumbell rows 3 sets of 12,10,8,6 then a set of 12 using the weight you used for the set of 8
Straight arm pull downs - same set sequence as above
lateral raises - same set sequence as above
pec flyes - same set sequence as above
dips - same set sequence as above
incline dumbell curls - same set sequence as above
forearm curls - same set sequence as above
the emphasis is on building the anterior muscles (traps, lat's, rhomboids, rear delts)
the other exercises are to build balance in your upper body. You'll notice that there's nopushing movements except dips.
Thats to allow your anterior muscles to catch up.
Proper rotation off the wrist during dumbell curls are important so check your form on this.
Day2
if there is a day2 will be legs
day 3
off
repeat day 1 &2
Off 2 days.
check out this site
http://www.bodyforlife.com/exercise/animations.asp
for detailed exercise descriptions.
If at any stage you feel pain, stop.