<human>: I am 29 and have been shy with women for most of my life, though at the start of this year I begun my first proper relationship with a 28 year old.  This ended, amicably, about a month ago though it is still clear that I have a lot of learning to go when it comes to 'Relationship/Emotional Intelligence'.

Fast forward to last Friday and when out drinking with some friends in a metal/alternative music club. A 21yo from my college course, Helen (not real name) was also there, we both knew each other was going and had agreed to meet up there(isn't facebook great).  My ex had pointed out to me earlier this year that Helen found me attractive (I was oblivious to this).

A combination of my own naivety, alcohol, and loneliness led me to take advantage of Helen and bring her back to my house, drunken sex was had. When I sobered up in the morning I didn't have the balls to make it clear that it was a one-night thing and I tried to act normal and accompanied her home while we chatted about college-stuff. I left soon after arriving at her place.

I thought I was better than this - but clearly I'm not.  I'm posting this because I feel like I should apologise for something - I feel guilty about what happened and I know I have a responsibility to face up to what I have done.  But should I apologise in person? By text? At all?

Feel free to ask clarifying questions.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Hooked up with a friend while drunk; Now feel too guilty to sleep. Not sure if I'm just being neurotic or actually a bastard.