The earlier episodes you describe of dizzy spells & greying of vision could be due to Syncope
or pre syncope. The episodes are brief & lasting few seconds to a minute.
The more recent episodes could be seizures or syncope.The prolonged period of unresponsiveness, lack of memory for the previous nights events and other accompanying symptoms raises the possibility of seizures. Visit a neurologist
who will be able to perform an EEG, Brain imaging & other tests which can help in confirming the diagnosis. A cardiac evaluation for any cause of blackouts is also necessary.
Hope this helps.