I get frequent headaches several times a week nd all my dr. Does is tells me to take imitrex (sumatriptan). Could something else be wrong?

Yes. Yes, could be an occlusal imbalance contributing to TMJ and migraine symptoms? Have you ever been examined by a dentist trained in TMJ headache management?
Yes. You may be addicted to analgesics (pain medicines). When you miss a dose, you can get headaches.