i would bet you have long covid based on these symptoms.
i have been where you are, going through every blood test, lots of CT and MRI scans and finding everything inside normal. looking for everything without accepting the obvious.
there is a lot of good information on this site. follow up on the links that relate to you. it will give you ammunition to deal with your health providers. continue to be insistent. thank them for their concern and all they doing for you.
last year my health provider set up a Long Covid group in my area. i was referred to it and it has been very helpful.
this process takes good luck and persistence.