Hi @nathansmith7143. First so sorry you are going thru this and thankful you have found this site. Everyone has insight and thoughts to hopefully help you. My head pressure/cognitive symptoms with post covid sound like yours. Ruling things out took years for me and led to histamine reaction as one attributing factor to it. It takes time and diligence noting foods, reactions, symptoms to get full picture yet worth the knowing and ability to adjust foods/spices/activity to relieve indescribable pressure/pain and cognitive impact. Wishing you the quickest relief and healing journey🌈