I just saw some pics of 2 years ago, I was 17 at the time, I had a square perfect hairline with a bunch of hair, basically perfect hair.
I got into fad diets and did low carb/keto diet for a while, which are known to destroy the thyroid which causes hair loss. On top of that, I got into a fair share of stress during this age. I remember running my hand through my hair and getting tons of hair out.
As of today, I stopped the shedding after getting off the fad diet. I don't see any shedding in the shower, and I only see a few hairs whenever I run my hands through my whole head but that's normal. I'd say I have very little shedding right now, or basically none.
The issue is to regrow the hair, which I don't know if it's even possible.
I'm located in Spain