If your very serious girlfriend was casually chatting with a few male friends online every now and then(one of them being almost ten years younger than her, and in a very serious relationship themselves)would you feel threatened by it?
It doesn't bother me at all. So just because you and this bloke are together you have to cut every male friend out of your life? Nah, this is bollocks. For the record, I wouldn't out up with this kind of controlling behaviour for a second.
Would you accuse her of being unfaithful? Would you basically come out and call her a whore? Would you be willing to lose this person whom you claim to love more than life itself over this situation? Would you get angry and constantly throw in her face that you yourself don't talk to anyone online but said person?
Luv', if I said those things to my girlfriend, her father would put a bullet in my knee cap. (No, I'm not kidding. I honestly believe he capable of it.) But for the sake of this discussion, if my gf's father didn't scare the living daylights out of me, I'd still wouldn't say those things. A relationship is built on trust and respect, without those two things, you might as well high tail it outta Dodge this moment. From what you've posted now and in the past, I'd say you should cut your losses.
And if he claims he doesn't talk to anyone else online, he's full of it. Ask him when was the last time he used Facebook.
Tell me, please, am I really in the wrong here? Because I sit here feeling like absolute shit, feeling utterly useless, feeling that I honestly did something wrong, seconds away from losing the love of my life, and I do not know what to do.
You are
NOT in the wrong here, luv'. And quite frankly, this bloke sounds like a right bastard. And as someone mentioned before, this is the kind of behaviour that escalates into abuse.
Now I'm not saying that this bloke will do the same thing. But the last time I saw a situation like this, and i foolishly let it escalate, it ended with one of my best friends in the hospital with a broken jaw, tree broken ribs, a punctured lung and various cuts and bruises. But thats a whole 'nother story.