Scrape the tongue, there's a build up that's shedding, it feels like hair. And if there's a lots of white build up, detox with Lemon water or Apple Cider Vinegar water for 7-10 days. White tongue is build up of yeast. https://www.aaom.com/hairy-tongue
to get in my mouth also, crazy I know. I was on antibiotics recently for a really bad congestion problem and the hair feeling stopped. As soon as I came off the antibiotics within a day it started again. I think it is caused by mold spores or fungus in the air, .
I feel like that sometimes too,maybe a dentist could answer why this happens.
I also suspect mold spores. There is one other thing, Sounds crazy but check the inside of your bottom lip and cheeks sometimes for anything that looks like a tiny blood blister. Also check your tongue carefully for a tiny micro black dot that looks like a black pepper flake. Especially if you feel a sore on your tongue. If you find either of these carefully take a tweezer and remove them. I have done this, I still think it could be a spore. When I remove them that feeling of a hair on my tongue goes away for a while. I first thought the deep red spot on my bottom inner lip was a blood blister till I saw a couple on the inside of my jaw as well . I then got the new tweezers and barely grabbed the blood clot thing and pulled, just too see if it would bleed out. Weird thing is It came off and left a red spot like a leech would do. I know it sounds crazy, but I swear it's true. I put it on a paper towel and after a while the bloody little speck was just a clear whitish speck like it absorbed the blood and now was just a clear opaque speck. We will never know what it is.