Matthew Wood is a well respected practitioner of traditional western herbalism, international educator and author. I have studied with him for years and absolutely love his books. I would trust my life to his herbal knowledge and skills.
Find information on recommended herbal treatments for COVID 19. He recommends Angelica, Lomatium (which is what came to me for this), elder, ginger and thyme among others. Read more in his FREEBIES, COVID 19 articles offered for FREE when you create an account on Matthew Wood's site Matthew Wood Institute of Herbalism.
Ginger and thyme (as I have been recommending) are easy to come by. I recommend taking some in tea form (or food) daily. I am recommending thyme preventatively, 1/4 t per cup of tea of dried herb or 1t fresh thyme per cup. If you get sick you may want increase, particularly if you are feeling relief from it. Matthew Wood does explain some tongue indications to watch for that would indicate changing dosage of the herbs if sick.
Thyme is in my Sweet Dreams Tea.