Mercury poisoning diagnosis?

I'm on the 3rd "Long COVID Specialist" - all from teaching hospitals. No one agrees on what's going on. One said "Mercury poisoning" which I think is their response to all things - they also deal w/ geriatric medicine (and I'm that age group.) Because they went through it, they think it is all of us. The number of supplements "recommended" - well, on paper all of them but no clear direction of what to prioritize to take - and other things that made no sense esp when lab tests came back with NO mercury* and no heavy metals at all.

*I know that older fillings can create mercury poisoning and I'm not spending the money on even the few fillings I have. I'm exhausted generally and from all the recommendations AND the cost of supplements that are NOT covered by Medicare or supplemental insurance, it's too much. Curious tho' if others have heard this as a potential CONTRIBUTOR to long COVID. Thanks.