Good on you for coming forward, but I fear you did for the wrong reasons. You talk about how you've changed, but you ultimately admit to it now to get attention. You make yourself to be the victim in order to receive the validation from others telling you how great and brave you are for stepping forward. To be honest, I'm not sure you should have posted this so publicly. It's a pretty personal situation that you're advertising. So, yes, I'm inclined to believe you posted it for attention.
I can tell you genuinely feel bad for your actions though. And that's just part of being human. We make mistakes and then feel bad about them. However, in your post, you kind of divert from what you did and focus just on how you feel about it. In doing so, you are diminishing the gravity of what you've done, and the fact that you clearly hurt Pendio--and dismiss his feelings for your own. While you do acknowledge you have wronged him, and even hurt him, your fixation on your own feelings over his makes the entire post come off as extremely selfish. No reason to make him feel bad that you feel guilty. Because you are guilty. You did do what you did. I'm glad you learned from it, but please don't overestimate peoples' ability to put friendships back into the state they were before things went wrong. Because that's not a thing. There will always be a difference between the before and after.
All you can do is acknowledge what you did was wrong and move on. You'll do more harm to both yourself and Pendio if you dwell on it too much. Posting this six months after the fact isn't healthy, as you're bringing all of this back to the surface. The façade you put on during those six months, that everything was ok, and then you dropped this? You should have been more open to Pendio during the period after the breakup, if you truly wanted to "end his suffering."
I don't want to come across as some grouchy ****head, but I just can't say I agree with your thought process here in posting this. I'm regrettably familiar with the writing tactic I see used in your post, and while it may not be fully intentional on your part, I can say that it was at least carving at the back of your mind while you wrote. But, I do know things will get better for you and Pendio both. But you need to accept what happened before they can get better. I don't read your post as "accepting and moving on" so much; it's more a "I did this and I regret it." You'll need to assess that, and come to terms before the true healing process can start. Best of luck to you, though. I am here to support you and Pendio if either of you ever need it.