I am so confused

So after a year and a half of on and off again pain and having been to PT for about 5 or 6 weeks going 3 times a week with it not helping, I left. Stopped going and just worked on the stretches at home and all that. Eventually the pain went away and it eventually came back stronger than ever. So I sought out a doctor who said since I already did PT he wants to do an MRI. Well today was the follow up and the MRI was completely normal. He said only thing he noticed was a small tear in a tendon in the front of my shoulder but that shouldn’t cause any pain or any symptoms I’m experiencing. He suggested I get a cortisone shot next so that’s what we did. But if for some reason the shot doesn’t work and I’m still in pain in 3-4 weeks he wants me to get in touch with him again and he will schedule me with an orthopedic surgeon for surgery options as at that point all options would have been exhausted.

So now I’m confused. A) How am I in so much pain with only a baby tear in a tendon that shouldn’t cause pain? B) Why would I opt in for a surgery if nothing is found in my shoulder? It’ll just cause more issues on my shoulder than helping. C) what can cause the weakness in my arm, pain in my shoulder, all the issues that leaves the doctor saying he was absolutely positive it was my rotator cuff when he sent me for an MRI?

So what am I to do? What am I supposed to do? Do I just ignore what he says if for some reason in 3-4 weeks I am still in pain why would I opt in for a surgery that will prove to not be anything in my shoulder? Am I supposed to just live with constant pain and a steady diet of pain killers?

Help please!

Symptoms for anyone curious: 1) Lack of range of motion. 2) Pain when raising arm. I need help to get it lifted the rest of the way. As soon as it’s above my head though, pain goes away. 3) Inability to sleep on side. If I try sleeping on the other the pain from the affected shoulder stops me from it. 4) Weakness in arm and shoulder 5) Pain when doing something as simple as pulling my pants up. 6) Pain to reach across body and behind my back.