I think its good that you've stayed and i think you can both come back from this. No life changing decisions should be made while under immense stress.
It sounds like you both could get along better with some marriage therapy. You have 3 kids - thats stressful and you need good communication to function as a minimum!
Why not say to him something like: "look weve had a really stressful time and disappointing for us both. I think we could both use some help navigating disagreements as we've both been very upset. Anger comes from sadness and ultimately Im sure were both very sad with how things worked out. So Id like to try marriage counselling so that we can give ourselves the chance of being a better team together. I respect that your a great Dad and Im a great Mum, Im sure we'd both like to be a great family together if we can try. Id like to explore if we can come together and work on our communication, im sure we both think were worth trying for. Lets set aside talks of separation until after we do a few months of marriage therapy"
You can source marriage therapy on "bacp" or "counselling directory" websites. Choose a psychotherspist, not just a counsellor and pick an older lady for the life experience.
You dont owe anyone on musnet an ongoing update on how you are now going to separate after a very bad disagreement.
If i was you I'd drop the rope on this, try and open lines of communication and express a desire to work together. Be open that you were tired and hurt and likewise so was he, you can say that for him as he may not be comfortable being vulnerable. If he knows you are dropping the rope, i think theres a good chance he will come and meet you half way.
Its been a very stressful time going on holiday while you are both in a very stressful chapter of both your lifes with 3 young kids. I do think next time try centre parcs or a couple of short Haven breaks to alleviate the stress of travel.
Ultimately neither of you are robots and you have both creaked under the stress of this exoerience in different ways. This doesnt mean you now need to divorce.
Step back and breathe, recognise how you have both been stressed, set divorcing aside, arrange marriage therapy and choose to put your energy into working together.
The dust will settle between you both with every passing hour. You dont owe mumsnet a separation. Yes his behaviour could be categorised as abusive but equally do could yours, neither of you are perfect but you were both tired and stressed. It doesnt mean he is an abuser or that you are.
Youve both made bad choices under stress and are lacking communication skills, not ideal I know but totally fixable.
Just slow down and consider what Ive said, then Id probably ask for this thread to be deleted so you dont have lots of people telling you to separate and wanting status updates, its not healthy for you or your family.
All in my opinion of course. Good luck to your family x