Hmm. Okay, sounds like you need to consult a divorce lawyer well before you talk to your H, but also, as some really simple practical matters, plan for the first day or two if you have to flee as you describe. Beyond the first day or two the law should swing in behind you and keep you in the home (but see what solicitor says). And meanwhile:
can you move some money to where you can access it without his cooperation for immediate expenses? create a new account and siphon some money off -- be clear, not to hide it from the courts forever, just to have cashflow for the first few days, at least for a hotel room, at best for a deposit on a rental. (Though I agree with PP: the law will, I'd guess, hold that you and DC should stay in the house pending any sale.)
Financials are of course the most important, as well as papers if DC have passports, if you have important papers, put them with a friend or relation. (I have done this for a friend in crisis.) Make sure you have evidence scans, photocopies, phone photos at least -- of any crucial evidence of his income and assets if you can; also, photograph important items you can't easily move out in advance: the painting of your grandmother or whatever? Indeed, if you have time, put your phone on video and move through the house conducting a basic inventory of what's there. It will help you remember what to retrieve, or provide some level of proof of your standard of living. Think as if you were doing an inventory for insurance, but without the faff of all the paperwork.
likewise, plan out the moment you tell him, too. Ideally you'd do it while DC are NOT there (with family or friends or at nursery) but also have witnesses physically there so his "outbursts" are either contained or at least witnessed -- again, parents, friends, worse comes to worst a public restaurant or even a park?
and, just in case as you say you do have to flee, have your car key in your pocket and last-minute necessities in the car ready so you can just get in with DC and NOT have to carry luggage. I'm thinking things like their stuffies or favourite jammies or whatever comforts them in a time of stress. (Don't forget whatever you need in a time of deep stress.)
All this may be overkill. But if he's reasonable, then it won't matter if you over prepare. If he's not, best be ready to flee, as you put it.