Rotator Cuff Burns when i lift, Arm feels like its falling out of socket, Please He?

Roughly year ago, i did Lat pulldown behind head and hurt my left arm because it couldnt pull down, the shoulder burn for a week and then pain died down. But when i lift now my arm feels shaky, specifially the rotator cuff is weak, and also when i walk it feels like left arm is falling out of socket, like hanging out. Trying to strengthen cuff with massage and light r.cuff exercises, and i tried to pop my arm in so it feels a little better, but i have this problem for a year now. How to deal with this please?