Internet Relationship Drama

Should I be mad at my best friend?

Okay, stupid question. 
I met this guy named Richie on this anime website I used to post on. We were both 17. We had everything in common, our likes, our dislikes, our personality. Richie is in a band. he didn't get to talk to me much but we were in a relationship for a little over a year.
My best friend loved him for a long time. She made no  secret of that. I started to get distant from Richie and eventually broke up with him. Just like I thought I would do I started to feel guilty and tried to go back but soon figured out that I'd been dumb and now I had to pay the price for my actions. 

Soon after they started getting closer. I think they're together now but I haven't asked her. We haven't talked very often but are still very close. Things have been crazy and I had to get rid of my phone and stuff so not much communication going on here. 

I won't deny it I am jealous. Even though it was MY fault. Sometimes I am mad at her because sometimes I think that it was her fault that we broke up. Then I realize that I'm being a baby because I was the one who started loving someone else.

Every time I get into this mood and come out I realize just how messed up the human race is. We are all selfish beings. That is why we cheat. I admit that I was cheating on Richie the whole time (excluding the time before 2007 because I didn't have the nerve to talk to the other guy until after the New Year).  I do feel guilty. 

there was a time (it comes and goes) when I actually hated her because they are together (maybe) 

oh by the way I wasn't dating the other guy we've just been friends. But so far as the heart goes I was cheating on Richie. 

I do still want him back but its never going to happen and I'm aware that internet dating the way I was doing it is dumb. I know that i shouldn't get into another relationship online. They're just not for me.