Metalhead ... the answer would be "yes ... but".
My first love is and will always be classical music in which I also practice (musician here).
I love Metal-Music but as with all styles of music: The love for a genre doesn't exclude the likeness to other genres as well it does not include EVERY style or band.
I especially like progressive metal (Haken, Special Providence, Animals as Leaders, Sympony X, Myrath). My first REAL contact with metal though was Nightwish with "Nemo" on MTV, though my brother already listened to metal before me so I may have gotten "infected" before that.
Born in a family of musicians I am though (like said) classical fan "by birth". I am a singer, organist, lead choirs ... you name it.
Due to my studium to become a musicologist I though began to respect other genres.
Rock, Punk, Funk I already liked before. But even pop or (german) hip hop I can digg now.
Nowadays my music collection contains a veriety of: Mozart, Bach, Schubert, Babymetal, Nightwish, Disturbed, Ayreon, Space One, Gacharic Spin, Waggaki Band, Omnyouza, The Beach Boys, Värttinä, Knorkator, Rammstein, Die Ärzte, Fettes Brot, Die Fantastischen Vier, Die Apokalyptischen Reiter, Schandmaul, Indila, Die Toten Hosen, Abba, Björk, David Bowie ... ect. This list is long and didn't even include the Soundtrack-Section yet (never mind if Movie or Game Soundtracks).
So ... am I a metalhead? ... Yes, but ...
Ah but due to that at least one of the characters of my comic is a metalhead (Haruka). Favouring Bands like "Sabaton" or "Týr" for example. ^^