Dear John,
I never thought I'd see this day. I am always the one who never believes in this sappy crap. Yet, here I am. For what it's worth; I'm sorry. Sorry for everything I did, for breaking-up with such a great guy. You were so perfect. I was so stupid. I've done a lot of growing up since then. I really miss you. I never told you this, due to our speaking terms, but whenever I had seen you around with her, my best friend, it broke me.
That time when you said you didn't care about me anymore was the worst thing I had ever felt. Which lead to drastic decisions that I later regretted.
But I won't blame you. I'll blame me, which might be worse. I have to see you everyday and everyday that kills me. All I want to do is go up to you and hug you like old times. You were pretty much everything. But be certain that I am sorry for everything.
Most of all, I'm sorry that I let you believe I was good enough. Not that you will ever read this letter. I guess this is another bunch of things I'll never say.
All my love and regret,
You know who.
May as well use my real name. John. Haha. Nah not really.
Wow! I'm agreeing with Livia. That was AMAZING!! You really put your emotions in there. The short sentences were so simple, and yet you were able to put so much meaning into them. Really great job. It's very moving, and I have to say, I can feel your pain. 
Sheer awesomeness and a million gold stars!