Shoulder Injury from running

[Deleted User]

I've just done the great south run (my first ever race) and whilst my legs are a little stiff; it's my right shoulder that's in agony. I can barely lift it to the side or in front of me. If i do and grimace the pain i can feel a "click" and it feels much better. If i try and massage the joint I can feel a lot of movement and generally it eases the pain. Does anyone have any idea what i've done /what i should do !?