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.
lexicologist.
Racist
Morbid.
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!
A person who is obsessed with dates is called a "chronophile."
crazy cat person
Custy
a shoeaveor
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.
A person obsessed with water may be referred to as a "hydrophile" or "hydrophilic."