Having head pressure everyday at the back of my head which feel blood circulation shortage, had mra/mri of head/neck. Both negative. Lightheaded?
Chronicity. The prior term, chronic daily headaches, now migraines, may well be applied to your pattern. My thoughts, assuming you have no jaw, neck, dental, or sinus triggers, would be to place you on a trial of an anti migraine agent, and would opt for an OTC prep such as riboflavin, CoQ-10, butterbur, feverfew, magnesium. Hope this helps.
Muscle spasm. Now that bad things have been ruled out, time to have exam for superior trapezius muscle spasm and possible therapeutic occipital block. See an osteopath or physiatrist for diagnosis and therapeutic advisory. Massage, acupuncture, muscle relaxants, and biofeedback are some of the approaches to healing.