Panicking over nothing? (Pics)

[Am96]

Hi everyone,

So recently someone joked about my hair "thinning fast" for the first time (I'm 21 for context), safe to say it unnerved me and reaction in the last couple of days has been a wee bit pathetic, panicking and checking daily etc. etc. (not my finest moment I'll admit!)

Doing that I came across this site and thought it would be a good place to show my concern. Basically in my fear-induced checking I discovered a thin-ish patch on the crown. It may have been there for ages but since I've only just discovered it it has scared me. So I ask, am I panicking over nothing or do people think this is a sign of something more?

Happy to post more pics/info if people can't tell from this and thanks for everyone's patience and help!