an astro nut!
This person suffers from a "Fatal attraction". Someone who doesn't really love the person, but thinks they need them to survive. This person can get extremely jealous and violent if you rid them from your life. So you need to be careful and seek help. They will stalk you, threaten you and try to bring you down to their level of emotional distress.
Well it depends. If you're a man and you're obsessed with another man well it's called being gay. And if you're a girl and you're obsessed with men it's called love!
crazy cat person
Not thinking independently
A person that loves all things French might be called a Francophile.
A person that hunts dinosaur bones is called a paleontologist.
It could be a chronophile (one who is obsessed about time).
an obsessed person is somebody who only thinks of one thing and does it all the time