Hi. So nice to meet you here
Post viral syndrome, which is what you describe and are experiencing, occurs with many viruses. It's not exclusive to COVID-19. You have the symptoms and are doing well by progressing. I wouldn't consider your any lessor of a candidate for great improvement then anyone else. I believe you can improve greatly. You're already on the right track of nutrition and knowledge. Go for it with positive expectation.
I support the supplements list with the exception of L Tryptophan for you, in that dose or at all, bc of your age. It's highly brain sedating at night and that places you at risk for falling. Not worth the risk. It doesn't help the post video recovery if you are able to sleep reasonably well. And it's truly potent. I don't take it for that reason and I'm younger than you. I almost fell after getting out of bed from the effects and I don't have balance issues.
Added to this list, Magnesium is a big helper. It's inexpensive. There are many options of this but the oxide is least expensive + least impacting on the GI tract bc it's absorbed in the stomach. We are deficient in this typically anyway. It helps muscle function and brain. Also zinc, taken at opposite times as Mg. Same with calcium. They compete for absorption so take each with different meals or snacks.
The shortness of breath could perhaps be helped with exercising your lungs while at rest. Deep breathing with slight breath holding then full exhalation at your own place for several mins thru the day can improve your respiration. It helped me. See Dr Furman, YouTube.
Also, while comfortable + with good body alignment, if you could tolerate small efforts of large muscle strengthening using very light resistance (see internet or ask here) while breathing with exertion you could increase muscle mass and strength. Protein + collagen (powers or drinks) are usually necessary to make progress. But you could try it without for afew weeks to see how your body responds. We lose muscle and collagen while debilitated and with age. We need to consistently combat that when aging and during/after being debilitated. I take it daily.
I hope your taking a good dose of Vit D3 too. And coffee, even decaf or with a slight shake of caffeine is deemed good for us. Recent legitimate studies indicate Green tea has some antiviral benefits. These are all small positive steps but they add up.
I've ventured into the world of eastern medicine. I have obtained huge gains from one specific form + bioceutical of tumeric root essence called curcumin in the processed form of NanoCur. Sold on Amazon, a starter trial pack of 10 capsules is under $3.00. I would never take any other curcumin bc of contamination + fraud in this industry. This product is made in US and is pharmaceutical grade.
I hope you start your new supplement regime slowly so you know how each agrees with you. And expect healthy benefits for your efforts over time.
Praying for the restoration of your energy, strength and daily life. Keep in touch with us.
Blessing.