Will exercise help?

Hi 6 years ago I fractured my shoulder and in the last 2 years I have had constant pain and I am struggling to do much with my left arm. Anything that requires me to lift my arm is painful. 3 months ago I had a gel injection in my shoulder to ease the pain but it didn't in fact the pain is worse. I am now waiting for a shoulder replacement. Has anyone else ever had this. I have been given no exercises and wondered if they would help.