Alcohol, sleep and coffee

Guys, im heavy drinker, drinking for 7 years almost everyday. One evening, in 3 hours i finished 6 strong beers, got drunk and about 4 am i caught myself a doing a cup of coffee. I awake instantly and didnt understood why i was doing it. I started catching myself doing strange things at night while im drunk like hiding myself in some room or going for a walk naked through rooms. Somebody can explain what is happening to me and why im doing this? Sorry for my native english