Hi…..I was , am often…riddled by mast cell activation syndrome brought on by all the covid shots…….I have had a year of trying to find the perfect diet to handle it and brain fog is a huge issue every time I have a flare. For me the magic came in Cromolyn Sodium Nasal spray by Healthguard, on Amazon. It was amazingly effective the very first time. I have always had sinus inflammation and basically skull inflammation, so this was a Godsend. I hope you try it. Everyone I’ve suggested it to for different reasons but principal for brain fog, has been so pleased! I think it has also been effective for me preventatively!!!