I just had two surgeries on the same shoulder for torn tendons. I wish I had got a second opinion before getting the first one. After having the surgeries, I have done the research I should have done before, and found out I might have been able to avoid surgery all together.
The original problem may have been what is called a frozen shoulder. A frozen shoulder starts out as inflammation causing extreme pain. The next stage most of the pain goes away, but the shoulder is stiff or frozen. The third stage is the recovery stage, with therapy the shoulder gets back to normal.
The problem is during the inflammation stage everyone is in great pain, and the doctors try a shot, but it doesn't work. Then you get an MRI and it shows torn tendons. The tendons are torn, but probably were torn for years. If you were very active in your youth, you probably have partial tears in your tendons, and have probably had some shoulder pain for years. It may be time to fix the tendons, but it may also be the wrong time.
Getting a surgery during the inflammation stage of a frozen shoulder can be like throwing gas on a fire, causing more inflammation, and pain. The shoulder gets more frozen, and therapy is more difficult.
I had to get a second surgery not only to fix the botched job on the tendons, but to unfreeze the shoulder. While under anesthesia they were able to move my shoulder, unfreezing it, then orthoscopicly remove the scare tissue created by the first surgery.
If you recently injured your shoulder and know when and how, than you probably tore the tendons at that time. If you can't really think of any one time you hurt it, than a frozen shoulder is a possibility
I am not by any means a doctor, and your condition may be completely different than mine. You also have the advantage of being able to get on average better medical advice in the US than I could get in Mexico. I am simply telling you my story in hopes that it encourages you to get a second or third opinion, and do some research, before getting a surgery. Make sure you ask your physician about Frozen Shoulder. They may say it isn't even a consideration in your case, but it doesn't hurt to ask.
As far as recovery from surgery goes, I was out of my sling after a week, and able to some physical work after 4 weeks from my second operation. I am working now 8 weeks post OP. but still haven't got full range of motion, and my strength is only 50% of what it was. 6 week full recovery time is a very optimistic prediction.
Again, please don't take my experience as any kind of diagnosis, or recommendation for treatment. I am not a medical professional. I only want to help you realize that there are many different opinions and procedures that different medical professionals may recommend. I simply want to encourage you to get more than one opinion, and research as many options as you can.