2 years with tension headaches last all day/headaches shift from the left to right side of my head/ shoulders are extremely tense/ pain radiate from back of my skull upwards towards my temples. what could this be ? what therapist/doc is recommended?

Multiple approaches: I advise seeing several practitioners. An osteopath and/or massage therapist can assess and treat structural imbalances. Physical therapy may help. Stress reduction techniques should help including biofeedback. Consider counseling to reduce anxiety. Try a good multivitamin with methylfolate instead of folic acid, magnesium (ideally magnesium taurate). Eat a healthy diet with organic vegies/fruits.