A: Why are you being in such a hurry? B: I’m worried. My exam starts in ten minutes.
Are you being describes temporary behaviour; starts refers to a scheduled event.
A: I am thinking of changing school. B: I don’t think it’s a good idea. You’ll be lonely.
Am thinking describes a current consideration; don’t think is a stative verb expressing an opinion.
A: Why are you being angry? B: My sister is always taking my clothes.
Are you being describes temporary behaviour; the continuous form with always expresses an annoying repeated action.
A: Tom looks very stressed. B: Yes. He is studying a lot these days.
Looks describes appearance; is studying describes a temporary activity happening around the present time.
A: Why are you leaving now? B: My train leaves in an hour.
Are you leaving refers to a present arrangement; leaves refers to a scheduled timetable.