If you think you possibly have covid. The top 4 things I recommend are (ask your doctor before doing any of these):
1) Eat a lot of potassium, like 2-3 bananas a day or drink coconut juice. If you are diabetic or prediabetic, then ask your doctor what are ways you can get potassium without taking in lots of sugar. (Many people with covid are very low on potassium, which causes heart irregularities. I was eating 1 banana a day)
2)Sit in the sun and take vitamin D pills (many people with covid symptoms for long periods of time have low vitamin D)
3) Take zinc and vitamin c (improves immunity)
4) Buy a spirometer to do lung exercises as much as you can. It costs $8 on amazon. Athletes use it to strengthen their lungs:
https://www.amazon.com/dp/B000PAR7KQ/ref=cm_sw_r_cp_api_i_aXg4Eb0GM0HRG