I don't think you should let it bother you.
I am a music writer and attend loads of gigs. I used to be UK Writer for an extreme metal magazine in new York, so I would fetch up at plenty of seriously hard-core gigs.
I am fifty-six, little hair, glasses, dressed in jeans and a shirt and jumper. No tats, no piercings, no shaved sections of hair, no braidings, no combats, no boots, no beer (I'm teetotal) so i stand out like a Rabbi at a Christening.
And I feel as cool as anything!
It's obvious I am there for the music, not a late drink and a perv. - you should adopt the same approach. People are very tolerent when they are having fun, so just go with your enjoyment. Who wants to dance or jump up and down to bands with a load of old fogies?
Not me!