OP, you had lots of sensible advice here.
What’s done it’s done and there’s no point in dwelling on it.You applied the same rules to him as you’d like to be treated and it didn’t work.
Sadly you have been had by your „partner”, bore him kids and to your own detriment allowed him to accumulate the assets.
Yes,kids will be upset(they always are when parents split up).They will get over it and they will get used to it.
However you need to think about yourself NOW as this is YOUR future. Your kids will be provided for(great) but you need to act now.
Check your state pension, you can buy some contributions to it (NI stamps)
Get a legal advice whether you have anything to gain from the set up you currently have.
Custody 50/50 if he wants(and NO bailing him out when he can’t drop off/pick up his kids)
CAO if needed (would be crystal clear re duties and obligations)
or you are main carer and hit the bastard with CMS.
Save up like mad and buy something yourself or go private renting.
No more propping up selfish dick of your”partner” with your labour.
And last- keep your cards very close to your chest. He’s not on your side and showed the contempt he has for you. There’s no coming back from this.
I’m sorry(actually not) to call this guy derogatory names but he’s not a decent human being. Decent human beings don’t treat their spouses the way he did.
Good luck OP 💐