According to the legend, yes. Both men and women were dtf, but he only had eyes for himself.

Did Mickey Mouse really have big ears?

Narcissus was an allegory for anyone who focused too much on their own appearance, there wasn't a literal dude that experienced the story in real life.

Whether or not the person is objectively or even subjectively attractive doesn't matter.

Canonically, yes. He was the son of a nymph, and was considered beautiful even as a baby. He got cursed by Nemesis because he spurned all admirers, and they petitioned for revenge.

I guess the story wouldn't have worked otherwise so yeah, he'd just be delusional in that case.

Fine as fuck, apparently

If you want a really interesting look at the Narcissus story I can't recommend highly enough a podcast called Alex Andreou's Podyssey, which covers the story in it's very first episode. It's a fascinating deep dive in the story, and the podcast as a whole is excellent. Well worth a listen.

Confusingly there is also a podcast app called Podyssey, so you could listen to one on the other if you wanted 😁