What Could Episode Of Memory Loss And Confused State Post Intake Of Alcohol Indicate?

I suffered a delirious episode after consuming wine, at lunch, with my friends. I was not heavily intoxicated. I could stand and was coherent, and considered fine albeit a bit merry by my friends. We had lunch and drinks over a 3 hour period. We left the venue to head home to prepare to go out again for dinner. It is at this point that I became what I consider to be delirious. I did not know who my friends were and kept informing them I had a dinner I had to get to, with other friends. They took me home to my partner who put me to bed. I slept for half an hour, then got up and proceeded to stand in front of the bathroom mirror for 30 minutes, brushing my hair, and conversing with my partner about philosophical matters and ideas that slowly turned to ramble. Very clear words, but not making logical sense. I continued to walk around the house in a trance like state, and was assisted to bed multiple times by my partner, eventually falling asleep and woke again in the middle of the night alarmed as to how I had gotten there. My last memory was having a lunch date with friends, and I was extremely confused and distraught about waking in the middle of the night with no memory of events. My friends do not believe anyone had access to spiking my drink which has been everyone s first assumption. We were in an empty restaurant, and I don t believe any of my friends would drug me. I am not on any medication other than pain killers which I do not take often. I had not taken any on this day, to my knowledge. I do consume high quantities of Alcohol on a regular basis. I was not considerably intoxicated on this day, however I had consumed alcohol. (approx 5 glasses of wine over 3 hours) I have experienced black outs in memory from heavy drinking before, but not to this severity or long period of time (Approx 4 hours, of which i spent wandering around my home and talking (rambling) to my partner) There is history of alcohol abuse and bipolar disorder in my family. I have not been diagnosed nor show symptoms of bipolar. I have a history of mild sleepwalking. I have a high stress occupation. ..am I losing my mind??