You said any advice is appreciated so here goes. Like you've said, you're a young, healthy teenager, so with respect to training I would treat this no different from how you treat any other respiratory infection... REST.
Whether you have a cold or strep or COVID, etc. your body needs a lot of calories to fight those infections. It should be prioritizing all the energy towards fighting illness. The tough part is a lot of the time with respiratory sickness, you lose appetite and can take on a big caloric deficit. What magnifies this fatigue even more is anything that takes calories away from fighting infection: running. Or any sort of training load for that matter. This, combined with the fact that cardio training specifically taxes the respiratory system a lot, which is exactly what is trying to recover from being sick, is why you need to rest.
I'm a mid-d guy, early 20s. Was down bad earlier this month with a sickness that turned out not to be COVID, but I just couldn't stop coughing and had a 103.high fever. I got sick on a Saturday night after a big workout that morning, felt bad on Sunday while I was getting tested and deciding whether to do my long run, took Monday completely off, went back to school Tuesday, and ran easy on Wednesday. So I missed only three days and haven't missed a day since. I didn't even feel like I lost fitness and was suffering in the running post-sickness. Three days taking care of yourself is not enough time to lose any fitness. Obviously your case could be more severe but the way you should approach it is the same.
Drink a bunch of hot water with lemon, black pepper, thyme, turmeric and ginger throughout the day. Sounds gross but all that stuff works wonders for your immune system. Especially if you're anti-vaccine, those values should align with strengthening your immune system in more holistic ways, no? This does exactly that. Zinc gluconate, vitamin D, vitamin C, echinacea, and electrolyte tablets will also give a big boost in your recovery. I do believe that fresh air helps too. If your living situation allows you to leave your room safely, try going out for a chilllllll 15 minute walk once or twice a day. Other than that just lie down and sleep.
At your age not long ago I was in the same mindset towards time off- senior year indoor my coach made me race the first dual meet if the season just a couple days after getting my wisdom teeth out, and I felt like I was being brave, tough, gritty, whatever. My mouth was bleeding for a lot longer than it should have been as a result. You're not invincible but you're also not soft for taking care of your body.