I'm glad you edited your post to make it slightly more measured.
By all means, be angry at the politicians who have acted terribly throughout the whole ordeal - the Prime Minister held the referendum for the wrong reasons (and seemingly no one sought to challenge him for this at the time), one of the figureheads of the Leave campaign took up that mantle for the wrong reasons, the Left did not voice itself sufficiently, and now that the entire thing is over both parties have descended into chaos.
By all means, be angry at those who voted Leave, too, although that will only get you so far.
But saying that "[no one in] the population of the UK spared a single thought of the wellbeing of everyone else in the union" is not only patently untrue (by a very wide margin!) but is no different than talking about whole immigrant or refugee populations in the same breath.
Actually, the irony just now hits me: That's basically complaining that a foreign population that blamed a foreign population for their woes is now causing you problems.
I sure didn't see the Remain campaign talking about the fact that they'd damage the EU. Still, you added that "no one in", not me - I'm sure there's a lot of europeists in the UK, but they were outnumbered.
Sorry, London. Sorry, Scotland.
And the EU isn't going to cut off it's nose to spite the face, don't worry about it. But the UK is not getting a deal like it had while in, and bloody hell isn't going to get single market access and banking passport without migrant access just because they want it.
Or any other special privileges. The Norway deal is as good as it's going to get, and even that may be out of reach.
This is not imaginary. The population of the UK voted (albeit by a very slim margin, and throughout a stupidly run campaign) to inflict real harm on the EU. I get that you, and roughly 16m people didn't, but 17m did, and another chunk abstained, so the harm is done.
And also "Cooler heads will prevail", yeah, just like they did in the UK. Cooler heads surely prevailed there.
The funny part is, Junker had promised heaven and earth to the UK not to leave. Because the EU seemingly valued everyone's benefit, even if that meant the UK was getting a better deal than everyone else - because the UK really had the EU over a barrel in negotiation in the last ten years, threatening to pull the leave card at every turn.
Expecting not to be negotiated against as aggressively as the UK itself did for the last few years is unrealistic. The "We'll leave then" card has been pulled so often it was practically blackmail.