You didn't, and that's the largest part of your problem ... your total lack of emotion.
You know what it would feel like for you to be cheated on yet you feel no empathy or compassion toward your boyfriend.
You know what you did was wrong yet you feel no guilt.
You know you didn't keep your promise of faithfulness to your boyfriend yet you feel no shame.
You know you should never do it again yet you feel no remorse.
These are all important emotions that you apparently don't have.
In fact, the only emotion you express in your post is that you are capable of lust.
I'm not sure what self-assessment insights you hoped to get from us because you had yourself pretty much nailed in your original post ... you are a selfish girl with no conscience.
Carl.
Look, xyla, obviously you wanted advice, otherwise why post here, right? And you got advice. So, what is the matter?
Yeah sure you hoped to spit all the bits here and just to feel relief and us saying 'don't worry' so you could feel even less guilt. BUT, life isn't like that, bitch.
Don't expect anything.