Problems lifting

When you say 'physio', does that mean physical therapy? Is your doctor a good bone doc? I had PT for tendon tears but it made things worse, the only thing that helped me was extensive rotator cuff repair after a rupture of one of the bicep tendons, and as a result have a dropped bicep muscle (only one still attached). The tears don't always mend themselves and it sounds like that's your situation. Shots of cortisone aren't always the best for tendons. Please don't be afraid to seek a second opinion about your shoulder,,,, lifting the kettle should be easy and not painful. God bless you.