October 2008: Subacromial decompression, distal clavicle resection, excision of calcific tendonitis in the biceps tendon at humeral insertion, and generally cleaning out a bunch of shreds and chunks of junk that had been building up for almost a decade of overuse. I also saw an Orthopedic Oncologist because for about 3 weeks they thought some of the calcification in my biceps might be a "growth". And I'll tell you, I'm pretty happy to have escaped with just a plain boring structural procedure.
It was 16 months before I was consistently able to engage in a wide range of activities without pain/swelling/tenderness/tightness/discomfort/tweaks/twinges/crunchiness. Now, almost two years out, I've gone 6 very physically active months without any symptoms whatsoever. In fact, my shoulder feels better now than it did for years before my procedure.
The worst part of the rehab was definitely ME and my difficulty laying off activity. I am a workout/sports/outdoors/adrenaline nut. There were dozens of times I would go to the gym and tell myself "It's okay, I'm only going to do light-weight high-rep exercises today, and tomorrow when I'm coaching my niece's volleyball team I can run all the drills without actually having to use my shoulder at all, and then this weekend when I'm helping Jeremy move I'll just help to pack boxes instead of carrying anything...."
Yeah right. SUCKER!!!
Once I'm in the moment, I'm gonna do 50 push-ups and lift at a big percentage of my 1Rmax, and I'm going to start hitting balls at the team during practice, and I'm going to see how many boxes I can carry up three flights of stairs at one time. And just for good measure, I'm going to suddenly get an irresistible urge to climb a really cool-looking maple tree I see while at the park.
Or at least, that's how I was until 16 months of looooong rehab with multiple setbacks and flareups finally conditioned me to slow it down a little. Just because I know I *can* add 30 more pounds to that lift this week, doesn't mean I have to, unless I really want to be all swollen up again to where I can't get the peanut butter down from the cabinet without wincing.
And yes, you kinda feel like an idiot standing there at the free-weight rack curling your little 5-pound Barbie weight for a couple months, but you have to get your mind to realize that you're not going to magically wake up one day and be all better and suddenly bench 240lbs 3x15 times with no pain. It's an incremental process.You have to tell yourself there's no such thing as "being buff someday", there is only "becoming a little bit stronger today", lather, rinse, repeat. But this is true in general: Being is an illusion, there is only the continual process of becoming.
I agree with the other advice you've been given. If you're still feeling weakness in your shoulder, ask for another PT scrip. This time, tell your therapist you want to focus on transitioning to an independent normal gym workout. I did exactly that 8 months post-op when I had tried going to the gym thinking "Okay, I graduated from PT so hallelujah I'm healed and can get back to working out." Nope, sorry. I could not do ANY bench-presses, push-ups, pull-ups, without soreness (the bad kind, not the normal muscle pump) for 12 months. And even then there was 6-8 weeks of easy incline pushups standing up and just leaning over against the kitchen counter before I started to put some bigger stress on it. And military press or any similar overhead lift was a complete no-no until just this past April. Personally, I discovered that I could do the decline press without going through any of the problematic ranges of motion. After two months of decline press, I incrementally leveled off the bench more and more until now I can do flat bench and dumbbell military presses with no problem (still at a decent incline with the dumbbells -- two different Orthopedic Surgeons and my PT told me they make a lot of house/car payments off of all the guys doing the perfectly straight up shoulder presses.)