In reply to iksander:
Shoulder cuff? Do you mean the deltoid or rotator cuff is injured? If it is the rotator cuff, have you injured the common tendon or one of the muscles?
If it is the tendon, it could be months/years to full recovery. If it is the muscle it could be 6 weeks+ depending on the injury. Recovery time depends on many things, rehabilitation program, diet, severity of injury, etc etc. The recovery time can be reduced with massage, and good rehabilitation, diet, and hydration.
There is no need to get weaker or fatter, just train (rehab) within a pain free range of motion. This could mean using bands, or weights rather than heading to the wall.
Find your nearest soft tissue therapist and get some treatment, unless you can reach the injury site yourself. In which case massage the sore fibres, if you cannot reach the site easily consider using a tennis ball against a wall or floor.