I finally wrote him a letter:
Hi. I know we haven't talked in a few months. I want you to know I have no hard feelings, and I'm not mad. I guess I'm just a little disappointed. I want you to know that even though we didn't date for too long, I have never fallen so hard so quickly for a boy in my entire life. And I don't know why I just cannot get over you. You're special, clearly, because I'm the pickiest girl alive. I also have extreme trust issues, but it wasn't like that with you. I trusted you immediately, wholly, and completely. Your kisses were my favorite and the sound of your laugh was (and maybe still is) my most favorite thing ever. I just want you to know you're special.
I know you have another girl now who's probably prettier and gives better kisses. At first I was upset when I found out you were dating someone else. Now I'm not. I'm actually very happy for you, because you deserved a whole lot more than what I was giving you. I can tell you're happy and you like her just by your Facebook posts. I'm so happy for you, and I hope you enjoy her.
If you could just do me one favor: Tell her she's lucky. Tell her to appreciate you and everything you are. Tell her she'll never know what she has until it decides to leave unnanounced, without responding to text messages and without returning calls. Tell her I am envious of her, but for the right reasons. Tell her I do not plan on interfering because I will not be 'that person' and because, somewhere deep down, hidden underneath all this envy and depression, I think I like you two together more than me and you anyways.
With whatever comes before love,
Chris