I suffered from long covid as well I think, which no one could explain at the time. Severe dizziness, breathlessness, couldn't even water the yard with a hose without my heart palpitating, random vision problems, buzzing in my forehead, constant and severe anxiety, and the list went on.

It has finally subsided after a couple of years, numerous dr appts and ER visits resulting in nothing ever being done other than verifying I'm in perfect health.

I did end up starting 5k UI vit d3 a day about 8 months ago, 100 mcg vit k2, and some L-Theanine supplements. I will say that if that wasn't part of my recovery (maybe I just needed time), I've only been sick once since then. It was bad, but it went away within 2 days. I had a terrible deep cough and sinus pressure, and we had bought tickets to Seaworld, and had already moved our date out twice since buying them, so I was not going to miss again, even though I was feeling horrible. I just bumped my vit d3 up to 10k and took some other supplements and some ibuprofen. As luck would have it, it turned out to be heavily misting and 40 degrees that whole day we walked around the park, and I thought for sure it was going to turn into pneumonia because the next day my cough was really bad. But crazy, by the end of that day, I was already starting to feel better, and by the next day was clearing up. I've never had such a short, bad cough, turn around like that. All that to say, I think my immune system is so much stronger now with the vit d3. I do get out in the sun a lot, but this was in the late fall.

Of course, speak with your dr about any changes to your supplements or meds. I had started vit d3 because my d3 level was 30, which is the bare minimum. It's now 80.