Hi there!
Well, without a clinical evaluation it would be difficult to determine the cause of the hip pain. Possibilities that may need to be considered include infections/ inflammations, bursitis, tendonitis, arthritis, capsulitis, ligament/ tendon tears, growths/ tumours, nerve impingement, avascular necrosis, fractures, dislocations, etc. I would suggest getting this evaluated by an orthopedician for an accurate diagnosis and appropriate management. Meanwhile you may try resting the leg with some tylenol/ OTC NSAIDS to relieve the pain.
Hope this helps.
Take care!