If this began after washing clothes and there was no fall or sudden tear, start very gently. Do these 2-3 times a day, staying within a comfortable range. Mild stretching is okay, but stop if you get sharp pain, worsening pain, tingling, numbness, or weakness.
Avoid weights, push-ups, forceful stretching, vigorous massage, and overhead activity for now. Exercise-based rehabilitation generally focuses first on restoring comfortable shoulder movement, then later on strengthening the rotator cuff and shoulder-blade muscles.
NHS shoulder exercise guidance supports pendulum and assisted movement exercises.
If you cannot raise the arm, have marked swelling/bruising, increasing pain, or symptoms are not beginning to improve after several days, arrange an in-person assessment.