Buddy, I was in the same boat. I wanted to find someone with all the same tastes. (I think you'd be the bigger fan of Megadeth and Iron Maiden tho hahaha.). The truth is, these girls are few and far between but they are out there! There's not any one, specific place where Rock n Roll Chicks Anonymous go for the night life, but they are definitely around. I found my rock angel at a wedding of all places, and the groom was telling me for years that she'd be a good match for me. Stupid enough, he forgot to tell me about her music tastes LOL.
If you don't find a perfect match, just know that millennials have a lot of potential to like classic rock, they just don't know how much they like it. They tend to think only new music can be good music. The part that's a tall order is adding the guitar/piano playing on top of that, because musical instrumentality is fairly less common in our generation.