Is this the beginning of thinning/balding or just paranoia?

Hi all,

I'm in a bit of a worrying situation since I know nothing about hair I have no idea what's going on.
I never really paid attention to my hair aside from the hairstyle but as I notice a lot of my friends starting to lose hair or even in some cases go bald completely I'm starting to worry.
I've noticed that could see some scalp on the crown area and my hair feels thinner in that area than the rest. This is where the paranoia comes in, I feel like my head has always been this way and I'm beginning to worry now simply because of fear and I can't get it out of my head. I notice the thinning only under a bright light and when I ask people around me if they see anything they just tell me that there's nothing and I'm stressing over it for nothing.
I probably lose around 20 hair in the shower and maybe 20 other during the day, I know some hair lose is normal but I would only feel safe if I didn't see a single hair fall out (which is impossible)
I'm 19 and I'd like an outside opinion about this situation because I'd rather take action now rather than stay in denial, balding at my age would suck.
I attached some pictures tell me what you think.
Much appreciated 😁