what can l do for tendenitis in my shoulder ?

Here are few tips:

Take rest to decrease the inflammation. Avoid the activities that cause inflammation.

Ice application is a helpful treatment of inflammation for several reasons. Ice can help relieve pain, reduce inflammation, and stimulate blood flow to the injured shoulder.

Do shoulder exercise. These exercises help to strengthen the muscle and help the shoulder move more efficiently.

Avoid overhead weight lifting, throwing activities, sleeping with the arm over or behind your head.