What Happened?

What happened to us? As far as I knew, everything was great. Sure, different than before, but we kept up with each other; we were both still involved. Maybe it's just the pressure that's been on you lately, or maybe I did something completely and utterly wrong. I know that's possible. After all, I am far from perfect. If I did do something, it must have been pretty bad to make you say that. I never in my life thought I'd hear those three words...and it was you, of all the people in the world; it was you who said them to me. I thought I had read it wrong, so I read it again. Still the same words.
Tell me, have we distanced somehow? Has this whole mess of life gotten us messed us as well? Perhaps it has. If it has, I'm sorry. Completely sorry, and I would...no. WILL do anything to fix it. I don't want to loose you. No matter what you think or say to me, I am not. giving. up. I promise you, this is not going to be like before. I am not going to loose yet another best friend because of living in different places. I've done it once already, and I am not letting that happen again.
Some people would say just to let it go, that you will come back around; but, if I took their advice, I would loose you. The stupidest mistake would be to "give you space" or "let you cool off". So, whoever you think I've replaced you with..well, you're wrong. Truth is, I could replace you with a thing in this universe. There is no possible way of replacing a friend like you who I've shared so many times with. All those stupid jokes and late nights watching our favorite movies. Irreplaceable. Absolutely irreplaceable. And I'm having a problem wrapping my mind around how you could think that. But to clear things up, I only have one true best friend.
And that's you.