I think i have tendonitis in my left elbow. what is the best way to treat this?

First try this: 1. Make sure that tendonitis or epicondylitis is the true source of the pain 2. Ice and nsaids 3, take a good hard look at activities, add stretching and non irritating strengthening to your regimen try to strengthen you r grip and forearm without loading the extended elbow with the wrist fully flexedor raised with resistance 4. See a doctor ot clarify 5 talk to a therapist or trainer.