Shooting. pain from back of left ear, down neck, and into left arm. 21 and relatively active. ekg last month was good. very worried it's a heart issue?

Evaluate Neck: If you are not improving have your doctor order a cervical spine mri. Many times a herniated disc in the neck can cause arm pain especially if you have not improved with the medications and physical therapy. If it is a herniated disc you may need evaluation from a spine specialist to determine what other options might be needed (injections, surgery, etc) to help reduce pain.