Usually heavy exercise or long anaerobic exercise
causes production of lactic acid inside the muscle as end products. This wears out muscles and it needs to be washed out by blood. So you need to give it some time by doing stretching exercises.
You have said it is 4 weeks since the injury
. Sometimes injuries may also make the muscle in highly contracted state, so that muscle feels like tight. This is a defense mechanism so as to keep body immobile to promote healing.
You need to consult a orthopaedican, get a XRay of shoulder.
Meanwhile you need avoid heavy physical work using your affected parts, give it a rest
Take some analgesics like diclofenac