Fab - hope you don't mind I've namechanged for this. But your DS sounds a lot like mine, and I am not that great at coping with him either. He's 8, and never knows when to stop - if its needling his sister, refusing to go to bed, not brushing his teeth, not getting ready for school, chasing smaller children in "fun" rough play - you can use "one word" commands, pleading, reasoning - nothing works. Often if he's told off he starts shouting how we hate him and will threaten to do something unpleasant(throw his shoe at a light, break something) if we don't retract our punishment. We did get a child psychologist to look at him a few years ago, who said he had ADD - basically his impulse control button didn't work very well. Anyway DH and I have realised we just shout too much and yes, at times, I've wanted to throttle him, and have been rough, and TBH absolutely filled with a desire to hurt him, just to get him to realise that his behaviour is just too much for me to cope - which has translated into rough behaviour (gripping his arm, dragging him along) which is pretty poor.
So DH and I have been trying to do "tag" teams - one of us is always calmer than the other, so if it all gets a bit out of hand, then I call him in and disappear for a bit. TBH this is the best thing, it's almost always true that one of us is calmer than the other. Time out for adults if you see what I mean.
Also tried chanting in my head "he's the 8yrold, I'm the adult", and also thinking more about what I would want if I was a hysterical 8 yr old - eg giving him a cuddle if he wants one but standing firm on the punishment (for example, removing treats/no TV/no computer/no book). Also trying humour (DS tried to argue that he was not "charging" his sister with his scooter but going around the potplant - I said - well, if I were a detective, and I heard DD scream and you shouting "charge" and then heading towards her, what would I think - would I think you were just going around the potplant for fun? He laughed.) Also not getting trapped by deadlines (DH is the worst for this - thinking we have to go, right now, and if we don't then some calamity will happen). Trying to be as organised as possible the night before so the next day is easier - the school run is a real flashpoint in our day (as is going to bed).
Lots of sympathy - if I'm tired or ill, its a lot worse. I hope you feel better soon.