Trust your gut.

I am a now retired nurse of 31 years. Retired due to getting COVID severely 2x. I normally dont even catch colds, but COVID really got me. There is a great deal they still do not understand about this virus and the long term impacts.

I have scarring in my lungs and kidneys, had myocarditis for 18 mos, had neurological symptoms and problems walking and was on oxygen. We are now over 4 years out from when I first got it and while Im not at baseline I am much better. However..........
The food intolerances, and Mast cell reactions continue and while those were there on a minimal level before Covid, now the list of what I cant eat is huge and the reactions much more severe.

Studies have shown an increase in things like this with Covid infections , especially those who had severe infections.

Read up on high histamine foods , try to avoid them. FYI left overs tend to have higher histamine... Try a diet where you keep to foods with 5 ingredients or less and no artificial colors or preservatives. Its tough but if it is Mast cell it will make a huge difference.
Finding a provider who knows much or treats Mast Cell Activation can be hard. Mayo Rochester really doesn't.

To be diagnoses with MCAS you will need to do some baseline Tryptase levels and then during or after a reaction be able to demonstrate an elevated Tryptase level that meets the criteria as well as the symptoms. Without the Tryptase elevation you wont get the diagnosis.

There are other things that could be causing these symptoms as well.
Id spend some more time trying to eliminate other causes too

I do have diagnosed MCAS with the Tryptase elevation and KIT testing
Avoidance is the best defense for most triggers. Not always possible.. but

Zyrtec, Famotidine , Aspirin, have been helpful. You can get Gastrocrom with is an oral cromolyn solution, but only about 20% absorbs through the GI tract, but it may help,
There is a sodium cromolyn inhaler that works well but due to the propellent its not available in the US anymore and you have to order from Canada. Its just an inhaled way to get the medication in and works better.

Keep pushing for answers. Good Luck