Am i going bald? or is my hair loss something different that can be corrected?

im a guy, and im only 17 years old, but i’ve noticed throughout the past couple months that my hair has been falling out like crazy. In the shower, or whenever i run my hands throuhg it, i always see a few hairs on my hand. my hair is pretty long (as far as guys go), but most of the hairs i see are pretty short. Id say its like 70% shorter hairs, and 30% hairs that are my normal length that fall out. I know my grandpa (on my mom’s side) went bald fairly early, but my dad is about 53 and he still has most of his hair.

One thing i did discover is that the har around the side and lower back of my head – the hairs that are resistant to balding – fall out just as easily and just as often, and there is no bald spot forming at all. I know my diet is pretty bad (really bad actually), and i dont excersize at all, but i want to change that. And i also have alot of anxiety and stress; i might actually have an anxiety disorder.

what can i do to try and stop this?