i have the exact same symptoms, so you're definitely not alone in this. it almost feels like i'm rocking on a boat but only in my head? sometimes if i'm reading something my eyes will just suddenly daze out and i lose my concentration. the spaced-out feeling is a frequent one with me as well. i went to the ER once over this and they diagnosed me with labyrinthitis, a very common, benign condition that causes all of the symptoms you described.
the good news is that vertigo symptoms are usually caused by things involving the inner ear. you might have some fluid behind your ears that is throwing off your equilibrium and making you feel like this. sinuses can also be the culprit; anything that doesn't drain out as it should can cause many of these symptoms for a prolonged period of time, even for months at a time.
i know we tend to catastrophize any symptoms that are head-related and assume the worst, but a vast majority of the time, they're only caused by minor things even if the symptoms they produce are very frightening. there are certain exercises online for sufferers of vertigo and labyrinthitis to get your brain used to the movements and to lessen the dizziness. once your brain becomes readjusted, the vertigo slowly gets better. it just takes some work and a lot of patience. easier said than done, i know. :)