Tendinitis varies in its seriousness. It normally gets better with rest. Vickie may be able to advise you on exercises that depress the humeral head relative to the acromion (subscapularis, teres minor, lat dorsi) and also scapular stabilising exercise. These should help.
Vickie is on vacation with limited, dial-up only computer access. She PMed me last night and said it took her seven minutes to download the most recent thread! She'll be back on the 17th.