I'm going to sound like a quack, but... I had long Covid for years. It was horrible. I said f it and started trying internet 'folk' remedies. Simply taking melatonin at night had me so much better in a month. I have mountain biked every day for the last two weeks it is awesome (other than my zero leg strength). Before that I didn't really even leave the house for 3 years. And I can think and write code at the level I used to again now that the brain fog is lifted. I think there were trials on this and they determined it didn't work but it's crazy a little bottle from the grocery store (USA here so it's over the counter) changed my life.