Try to remember that you are in control as to who or what comes into your environment. Say prayers and imagine the healing light of God filling up your body and your room. If we give something our attention we are also giving it our energy. So if you sense the presence tell it with confidence to go away and focus instead on something positive. When I do a banishing before I bed I will state that benign loving beings working for my highest good are welcome but negative beings are not. I then threaten them that if they dare linger I will throw them into the eternal fire of damnation where they belong! It seems to work. They even blew the candle out once as they scarpered out of the room! You are in control, not them.