I can relate to this (another ADHD'er, hello)
I can get burrowed right in a rabbit hole when I find something interesting. I'll have a good old read of conspiracy theories.some are interesting some are bonkers.
I think I'm 'saved' as it were, by the fact that I'm also autistic, and so my logic and attention to detail kicks in. So I can read and read... but then I think 'hmm actually that's fucking nonsense, these people are batshit' and I move on to something more plausible. Rather than envelop me, it becomes more of a 'people believe this bunkum, huh? Aren't people and how their brains work fascinating!' thing - for me.
I also have a friend who has 'lost' her husband to the whole covid anti-vax thing. He's convinced the Rothschilds/Illuminati/the 'Elite'/god knows who else are behind the whole pandemic, that we're all now chipped, vaccines deliberately are killing is to reduce the population and we're all headed for doom as sheeple... it is fucking bizarre. They're getting divorced. He was a normal, nice man before.
Anyway, enough of the me-rail.
OP regardless of his beliefs and how tightly he's got embedded into them (sorry dude, the earth is not effing flat, come on!!) his behaviour is having a significantly negative impact on you and your children.
Plan carefully. Get all your documents and paperwork in order (payslips, passports, birth certs, mortgage paperwork, bank statements, all that jazz) , do it quietly, and get them out of the house somewhere safe he can't get to. If you can without alerting him, start moving some money too, so you've got a safety net. There is a fantastic thread on here somewhere written by a woman who left her cheating arse of a husband and how she planned carefully first, I'll see if I can find it and link it but it should be a 'how to' guide for any woman who needs to get out.
Do not alert him. Careful of your phone and if he's monitoring it, or you. If he's starting to break things he's becoming abusive already and you don't want things to escalate.
Please take care, and get your shit together to get out with your kids.