So, basically you're willing to allow him to take your moronic ass back, when you haven't even taken the time to figure out why you went and fell in love with someone else while dating your boyfriend.
And, don't give me that "it just happened" crap. Because it doesn't just happen. You have to allow that person to steal your emotional energy and focus away from your boyfriend in order for this to happen.
Which leads me to ask. Why did you do it? If the answer is, "I don't know?" Then you're pretty much doomed to **** your boyfriend over again.
Do I think you're a bad person? Not necessarily. Do I think you're actively doing mean and harmful things to your boyfriend? Yes, I do. I think you're being selfish, I think you're looking out for your own wants and needs and not putting his before yours. I think you haven't sorted your shit out, and that you're unwilling to take a deep hard look at why you did what you did, and admit to why.
I'm sorry, I've been there. I've cheated on my wife. I wasn't out to hurt her, but I did it, and it was really shitty of me. I divorced her, moved on with my life. But the reason I did it was because I was ****ing miserable in my relationship even though I loved my wife. I was very miserable, very depressed, and someone showed me that I could be having a lot more fun in my life.
And, you know... You got involved with someone of such low calibur on the side that he was OK with dating someone who was already in a relationship.
I'm sorry, but... You suck, and you obviously don't care that you suck, and aren't doing anything to keep from further ****ing up your life and relationships in the future.
Fixing your serious problems while in a relationship, is generally HUGELY damaging to the relationship. Most relationships cannot, and will not recover from this. And, you're going to have to put up with a lot of shit from your boyfriend, for a very long time. Probably long after you feel you deserve it.
So, you ignoring people who tell you that you're a bad person? You're in denial of what you've done, and you don't want to face the truth of it.
Once you cross the line of cheating, it's never as difficult to cross it again...and again...and again... And soon it's habit.
Do yourself a favor, spend some time figuring your problems out, get some counseling to solve whatever intimacy issue is bothering you, and then see if you can't work things out with your boyfriend. That is, if he isn't off schtupping someone else already...
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."