Trion, tbh bro you dodged a bullet by getting away from this girl. First off that long distance thing is no bueno. I mean if you are in a volatile relationship as it is, plus you've got the long distance thing to deal with, you are just asking for heartbreak, either sooner or later.
Just looking at the situation that made you two break up, honestly it's bullshit. I'm married and my wife and I fight about bullshit like that all the time. Yet it's such a big issue that she's willing to dump you? That's not love, it's infatuation, and it wears off quickly. Besides she's grumpy until noon? Lol do you want to spend the rest of your life walking on egg shells? The relationship you are describing ny the way just doesn't sound normal to me, how long had you been dating when all this happened?
I understand how you'd like to have closure and figure out where it all went wrong, however there's something you meed to come to terms with. You'll never understand how women think, or the justifications they make to themselves in the decisions they make. It's just my opinion but I've seen women make a lot of mistfying decisions. In pursuit of trying to find out just what the hell was going on I reacted like you before as well. Trying to keep a sinking relationship afloat. However as the guys have all said, it's better just to let it go and cut contact completely im a situation like that. In fact the woman who I thought I would marry did something similar to me. After struggling like you with it I finally let it go and moved on. Guess what? That's right she tried to come back into my life later and even though I had a soft spot for her, it was too late I had moved on and met my eventual wife. Thank fuck for that because my wife is a real woman, she was just an immature little girl looking back on it (im sure she's matured by now but you can't waste your life away waiting for stuff like that to happen).
My wife is a psychologist. It's very normal for you not to be able to open up to your friends and family about these issues. It's the exact reason a person goes to a professional that is experienced with stuff like this. As you've already noted, just venting your frustration to a random bunch of strangers has already helped a lot. If you keep struggling, go and see a councelor or psychologist.
When i had an experience similar to yours it was a long hard road to get over it. However for me I took a piece of advice I was given and it worked wonders for me. "Just live better". Improve yourself and don't worry about what that other person is doing. I hit the gym harder, got in insane shape, I learned how to play guitar, i went surfing a lot more, and played football a lot. It's petty, but do you know how many hot women I met and fucked after that? Like I said when my ex came back to me and wanted in my life I had moved on and was dating a gorgeous intelligent woman (not that my ex wasnt, but it was gratifying after all she had put me through to tell her i had moved on)
So anyways sorry to ramble on about embarrassing details of my life, but the point was that woman did me a favor and my life turned out a lot better. Besides even if you do stay single think about all the benefits. You can do whatever the fuck you want without worrying about someone elses feelings.