Why do i feel tension and do i have the urge to stretch my left side.neck,shoulder, hand.btw i've been diagnosed with chronic cluster headaches.

Not so clear: True cluster headaches occur in older males, but a variety of migraine variants may cause diagnostic confusion. I wonder if indeed you possess a headache trigger area over left brachial plexus (thoracic outlet syndrome) or cervical problem (cervical stenosis). This will require evaluation by experienced neurologist, and likely confirmatory studies. Also, stop all tobacco use.