I thought about your post again since I found major relief in head pressure with changing my diet. I had trouble even reading things because of the pressure and I have gotten much better now. For me the major problem is bloating and the feeling that my body was not functioning because of a blockage somewhere in my belly. What I found is that when I switched to eating foods that are easily digestible the blockage gets less, my breathing gets better and therefore have less pressure in my head. I have experimented a lot with foods over the years since I know there is something wrong there because I always get reactions from certain foods. For example, the last 3 times I eat pizza I immediately get a blister on my lip. From meats like ribs and chicken I have had bad reactions, mainly pumping heart beat and not bein able to breath well, and waking up in the night. I do not know if you also have digestive issues or bloating? For me I had to focus on eating foods that are easily digestible. A whole food plant based is the way to go, plus fish and eggs (since these are very mushy and don’t cause blockage, meat is very sturdy). Most fatty foods are no good for me such as cheese or peanut butter, Nuts and eggs are no problem for me (probably because they are not processed). No bread, no cheese, no meat, processed foods etc. Focus for example on vegetables like brocolli, sugar snaps, sweet potatoes, normal potatoes, oatmeal, fruits like blueberries and bananas (no apples), fresh fish like salmon, plaice. I also eat prepacked frozen vegan meals like chili con carne that have a small amount of yoghurt in the sauce, the sauce is processed basically but that is no problem. Let me know if you too find relief.