Question) A handful of hair falls out every time I wash it. Is this hair loss?

Lately, I've been noticing a significant amount of hair falling out every time I wash it, and it's really bothering me. A handful falls out every time I rinse it with my hands, and it keeps falling out even when I'm drying it, so I'm shocked by the amount piling up on the floor. I don't think it used to be this bad, so since it's suddenly happening like this, I'm worried that I might be starting to experience hair loss.

I have been a bit stressed lately, but I'm confused whether that's the reason or if it's due to the season. I also feel like my hair has thinned out slightly overall, so I think that makes me even more anxious.

Is there anyone else who, like me, suddenly lost a lot of weight and then got back to normal?

I am curious about when it is best to go to the hospital, and I also want to know if home care methods or nutritional supplements are effective.