Diagnosed chronic migraine constant .every few months i get a bad flair where for up to six weeks i am completely disabled with the pain . im constantly nauseous, whooshing in ears and pain is severe 24/7 what causes these flairs and is it rare?

Chronic migraine patterns occur at least 15 days monthly, and yours appear more often. The immobilizing flairs may be associated with a variety of triggers including hormonal shifts, food or preservative reactions, and even changes in atmospheric pressure. What you describe is far from uncommon. See a neurologist and start taking CGRP therapy on a consistent basis to break up the pattern.