Was this a new place you moved into when you started having health issues? Are you feeling better in the new home? Also did you have the mold apartment actually environmentally tested for mold? Or it was just conjecture based on blood tests? I don’t know if I would buy it just based on blood tests, personally.
The thing with mold is, people’s reactions to it can be more or less severe. There may well be a mold issue, but you might not have had such a bad reaction if you hadn’t been on low-carb. It’s pretty common reaction to have allergies and immune conditions worsen on low-carb. My guess is it’s a bit of both. The mold probably is there (but it’s hard to totally avoid mold), but your reaction was made worse by the diet. Best to fix both in the meantime, I guess!