I Feel Head Pressure And My Vision Goes Black, The

I feel head pressure and my vision goes black, the other night was having those symptoms and I fell it was just like my body just fell on the floor. The next night i had the same symptoms and i just held on to the wall and not walked because i was afraid i would fall again, this time I banged my head on the wall three times and i remember it hurt but i had no control i couldn't stop my head from not hitting the wall. Should i be concerned?