First you need to see a qualified healthcare profession to determine what you have. You may have a ligament tear depending on what happened.
Studies on tendonitis of the elbow show that when it is chronic it is actually tendonosis (degeneration rather than inflammation). Several conservative methods can be employed-ice, rest, stop repetitive motion activities, tennis elbow straps, rehab, physical therapy modalities, etc. There is work being done by physical therapists and chiropractors using Cyriax's concept of cross friction massage using instrument assisted methods-Graston technique (www.Grastontechnique.com-I
believe). Most of the studies are being done by Physical therapists at Indiana University. I had one bad case of pain at 6/10 in severity for over a year and failed steroid injections totally resolve in 8 treatments.
Steroid injections are another option. If this is caused by sports I'd recommend seeing someone specializing in sports injuries.