A letter to somebody I used to know

Dear _,

I'm afraid we've reached the point of no return. The point where everything that has been building up for the past few years will come to naught. It's over. There isn't anything left to fix, because our friendship is beyond repair. At least, I think it's beyond repair. I already see it as a sunk cost, like a car that's been written off. And I don't wish to start over.
I think it's fair to say that we both tried to make it work. And for a while, it did. But then, this semester, everything began going downhill. What we did isn't working anymore. We've changed and grew apart. You said you valued our friendship. But I don't think so. Actions speak far louder than words, and all I heard was silence. I wish it could be better. I wish we could both just say sorry and move on. But this state of things requires far more than two "sorry"s to fix. Honestly, I don't even think it can be fixed. I don't want to try anymore. I'm done trying. You may say I'm being selfish. And maybe I am. But I can't try anymore. I can't trust you anymore.
To see our friendship end hurts me. Maybe more than it will ever hurt you. I will never know. I let you into my house, but you've only ever accommodated me at your porch. You know my every emotion so well, you can tell exactly how I feel with every small action I make, yet I hardly know what is going on with you.
You probably don't know what's it like to be hurt, have trust issues, swear never to let anyone in, then meet someone who makes you believe in people again, only to have them hurt you. Well then, let me tell you, it's similar to feeling like a fool for knocking into the same glass door everyday even though you take the exact same route to school everyday, but way more intense.
I give too much of myself, too fast, and often to the wrong person. To a person who will never reciprocate. To a person who doesn't care for it as much. Relationships are never 50/50, and stupid me is always the one giving 60, 70 or even 80.
I don't know why I said I was going to move. I don't think I'm in greater wrong than you. I don't see why I should be the one moving. I'm just so fucking unhappy here. But you, you probably don't give a fuck how I feel.