Who gave you permission to enter my room?
Correct!
About what are you thinking while you are taking a shower.
Technically correct, however no one talks like this. It sounds very unnatural.
More correct: "What are you thinking about while you are taking a shower?"
Did you marry your wife of your own will?
Correct! Strange question... but correct.
My father is in the habit of getting up very early in the morning.
Correct!
I am an antisocial I hate being among people.
Almost correct.
You can say "I am antisocial," or "I am an antisocial person."
"I hate being among people," is technically correct, but no one in the U.S.A talks like this. Maybe in the U.K. they would say this, but in the U.S.A. we would say, "I hate being around people."
Correct option #1: "I am antisocial. I hate being around people."
Correct option #2: "I am an antisocial person. I hate being around people."