I want to get a glass of water but im scared to leave my room how do I avoid this fear?

Just do it . Your thirst will be fulfilled. You will feel accomplished. This will prove there is nothing to fear. See a physician about this fear.
See below. Are you fearful in other areas of your life? You might want to talk to a psychologist or a counselor to figure out the origins of your fear and why the fear expresses itself the way it does. Meanwhile, just get a glass of water.