Sorry about your back problem. Getting old sucks! Especially for people who worked with their hands, legs, and backs toting that barge and lifting that bale. I've been sitting at a desk for most of my working life. Still, I do get sore working on the ranch a bit.

With DVTs and embolism history, the anticoagulent is critical and it will prevent clotting from cytokine storm. But it won't actually prevent the storm. Clotting is just a symptom. Steroids, like dexamethasone or prednisolone, calm the storm directly. Long-haulers seem to have very inflamed immune systems and a steroid gets it back to normal.

It's very difficult to get enough Vitamin D from diet alone, but you can get it if you eat oily fish every day (like some Scandinavians) or eat certain mushrooms exposed to UV light. Of course, in Florida you can get plenty just by mid-day sun exposure for half the time a sunburn would take.

Quercetin is in any healthy diet, just not much of it. People taking it for Covid-19 are consuming about 1000 mg per day, which is about 100 times as much as a good diet.