Hair ties, hair clips, hair pins, those spiral thingies you twist in (no idea what they’re called in English) and hairspray to keep it from fluttering about. Lots of ways to keep your hair up and in shape, depends on what exactly you want to achieve.
That said, I don’t know anyone, like literally anyone, who thinks that keeping your hair up is more comfortable.
Yes. Unsolicited dick pics are sexual harassment, regardless of who you’re actually sending them to. Also, I wouldn’t put it past people running scams like this to try and use your dick pics for blackmail.