Alcoholism is a progressive disease, for many years I would blackout when I drank a lot, the last 5 years of my drinking I blacked out almost nightly yet I never was really drunk, I had my teenagers take advantage of me more then once after they figured out I had no idea what I had said, done, or promised them in the evenings.
I have discovered that I have not had a single black out since I quit drinking.
You may never know what you did in that black out, all you can do is not have anymore to stay out of situations like this and the only way I can assure you of never having another alcohol induced blackout is to stop drinking.