A Spanner In The Fucking Works

Spoke to him this morning. Here's how the conversation kinda went:-

"Hey dude, up this manly chat then?
Yeah sure man, where you wanna go?
Anywhere, not bothered, let's walk and talk.
(we walk)
So, you first, you started the conversation on Monday
Yeah i guess i did haha. Oh dude btw, did you know I'm going out with **** ******* now?
(...ARE YOU FUCKING KIDDING ME. This is the fucking spanner in the works btw. I pause for a moment looking dumb.)
This doesn't affect our conversation does it?!

Nah mate! When did that happen?!
On Friday.
No way! Haha, you slipped her a finger yet?
Haha nah man.
Awesome lol.
So the question I asked on monday was something to do with your sexuality wasn't it? lol
 Yeah it was.
If you're gay or not. Because if you are, I don't care, I'm still your best mate and everything.
Yeah I know. Well I reckon I am. I mean,  I'm open to interpretation. I wouldn't turn down a smokin' babe you know. But vice versa for lads.
Yeah man. That's cool. Does anyone else know?
Yeah, **** knows so talk to her if you like.
Ah right. Makes sense. Well thanks man.
What about you? You said on Monday that you weren't sure.
Well, I don't know, I meant that, I feel comfortable enough in myself, and my sexuality to kinda, be a bit more, full on with lads.
(Heart sinks. And it's not melodramatic)
Ah right, I see. Well that's cool."

And that's how the conversation ran.
So basically I feel like a twat. I feel like I've constructed this romantic fantasy of how it'll all work out beautifully for us two. Bullshit. I'm so angry and annoyed at myself.
But also at him, for how he makes me feel. I would have given up SO much to be with him. I'm talented in my own way, and I would have given up this talent I have to be with him; this is the talent that I'd use to pursue my dream career. I'd become a burger flipper at McDonalds for him if it meant we could be together. I love him. I'd jack my whole life in to be with him securely until we both die happily. And to him, it's nothing. He says I'm his best friend, I can't be, he didn't even tell me he started going out with this girl!
And I feel sick with jealousy at her! Utterly SICK. It makes me so full of rage to think that SHE'LL be kissing him in public. SHE'LL be the one who gets his hugs, his attention, just him. She's only started liking him since Easter! Oh my god, I sound so fucking petulant and adolescent and fucking ridiculous but I don't care. This is what I'm feeling. Angst. Fucking teenage angst.
And to think that she's going to be his special one, that he'll lose it to. And I'll be left behind. I want to cry my eyes out because I'm so upset but I can't because I'm so angry as well.
Thought about telling him that I really like him tomorrow at college. Then thought against it, saying that it's not ruining what we've already got. Now I have no fucking idea.
It's just such a fucking shame. Because we could have SO much more. That could be a million times better than what we have already. I don't know. 
I'm sorry, someone else go. x