Almost cheating? Forgiveness

Long story short, i am married, love my wife And i would never want to Hurt her. Nonetheless, we were partying at 4 ppl with my wife, her BF and colleague female. This colleague IS our simultaneous colleague, she IS married, not happy. I have always had a good friendship with her, sometimes she touched me and kissed me even when my wife was close to us. This night we ended drunk at a room where were 4 beds next to each other, i slept next to my colleague. We were gently touching as many Times before (i guess in a friendly manner), but This time supported by alcohol i started to touch her boobs, she seemed she enjoyed it (closed her eyes and tried not to make any noise) and actually started to get her hands to my hair As an invitation to carry on. Then i moved Down, after a while she ended This (luckily). Now she IS distant, my wife doesnt know anything and i am torturing myself inside every day what a mistake I made. I would never allow anything like this when sober. Should i tell my wife I "Almost" cheated? At that situation, i was ready to do it (i know, alcohol and my dumbness) and i hate myself for this. Now i regret it a lot. My colleague i guess regrets it too and is distant. I want to repair it with her and get it Back to normal As it was - friends. Any sugestions? Sorry for mistakes. Btw I have never cheated in my life, always been faithful and never had problems with alcohol.