Such a person could be described with an adjective such as unemotional.
It's called bi-polar
Attributing your own feelings or faults to another person or group is called projection. It involves unconsciously assigning to others traits, motives, or desires that actually belong to oneself.
i believe that is called a low self esteem
Such a person is called a narcissist.
That is called overthinking, where a person excessively dwells on or analyzes a situation, often leading to feelings of distress or anxiety.
i think that it is called apathy also, people who do not have feelings are called sociopaths (Thats when they dont have feelings, so they kill others)
One word to describe your feelings for a person could be loving.
a characters thoughts and feelings is called direct characterization
I dont think There is any name accept for strange. But if they act on his feelings then this would be called Insest.
Then let her know of these feelings, if she still insists her feelings for another person, let her have him.
A person who has no feelings of emotions may be referred to as emotionally numb or experiencing emotional detachment.