See, that sounds like such a petty issue, someone used to normal relationships would go "wtf, he didn't put sugar in your coffee, so bloody what? Go and put some in yourself, what is your problem!" And of course, it could have been a genuine mistake... but when it's part of a pattern, not of forgetting, but an ongoing scenario where somehow what you want is the one thing you don't get, then you know, because you've lived it for x years and it so obviously isn't absent-mindedness. Once you've opened your eyes to the fact that it's deliberate, you see all sorts of things that previously you may have let pass. All that aggression he isn't showing at the moment (because he knows you won't put up with it any more) has to go somewhere. Mostly it's gone underground, to passive aggression, like "forgetting" little things that would make your life easier/more pleasant. But every now and then it surfaces in overt aggression. Poor puppy. Or poor Venus fly trap. Or worse, sometimes poor DCs.
Actually the best thing you could do in the situation is pretend you thought it was an innocent oversight, and either say coolly "oh could you please put some sugar into this" or, if convenient, go and add some yourself. "Oh it's very nice dear, only I usually take sugar." It will drive him crazy because it isn't driving you crazy! It's pathetic that we have to play these little mind games, but there is a sort of grim satisfaction in it. Temporary measure only, though, whilst planning The Great Escape. A normal person can't go on living like this and keep their sanity.