<human>: Can you give me a shortened version of the text?

This girl was my best friend for 5 years (ages 15-20). She doesn't live in the same state, but for years and years we talked for hours on the phone and Skype. It was one of the most significant relationships in my life, and in hers too she tells me. 

Anyway, we've both changed a lot. For the past year and a half we really haven't been talking about anything. Our conversations are dead and neither of us seems to want to be there, talking to the other. The only thing we talk about lately is how much our relationship needs work. 

I want to send her a message telling her that I don't want to stay in touch anymore and why. I don't want to call her because we're not good at these conversations, she's out of the country for a while, and I don't want to hear her cold "I don't give a fuck" voice. Hearing it makes me say stuff I don't mean. 

We both value honesty a lot, so I wrote stuff like "I'm no longer happy when you call, I dread it" in an effort to explain the need for us to cut off contact. But I don't know what to say really, nor what to avoid. 

Anyone have any advice for what to say in this kind of message? I want to make it clear that I'm tired of expending energy trying to save a relationship that's over. I don't want to try anymore. I still think she's an awesome person, but we're not able to talk anymore about the things that matter to either of us... so the relationship is over. How do I make it final without being dramatic or fake?
<bot>: I want to send my old best friend a message to let her know I want to "break up". I'm looking for advice on what to write. I know my end-goal. Is there a best way to get there?