“Pack a bag. Get your children. Go to your parents. Tell them everything. Stay with them and look at women’s refuges. Look at women’s aid. He’s abusive and you deserve better. He will try to manipulate you to stay. He may threaten allsorts. But he can’t get at you if you are strong. Having people on your side makes you strong and that’s why he has pushed you away from others. He wants you feeling like you only have him. He will probably insult you to try to make you feel like you’re worthless and need him. You don’t. Anyone can start again and so can you.”
This, OP. Given how little he does with the DCs, it’s very unlikely he will want or get 50/50. He’ll say that’s what he wants - he’ll threaten to keep the kids - but he certainly won’t get to keep them. You having been an SAHM and him being a shit dad works massively in your favour here.
As PP have said, what he’s doing is a crime. He has been very calculating in separating you from everyone. He’s tried to make you completely reliant on him. That’s how pre-meditated this is. It’s like there’s a handbook for abusers. You feel appalling because you are living permanently at a crime scene with the criminal. That’s why domestic violence is so hideous. You are living with your attacker, day in day out. Of course you feel appalling.
Don’t worry now about sharing care with him. It will be so much better for your children to be away from a house in which their mother is systematically abused even if they are with him some of the time. Over time, you will be much happier and more relaxed and that will be good for them.
It doesn’t matter what he tells people. Get your parents on side, reach out to a few friends. Speak to Women’s Aid. Speak to the police.
But first of all, get the DCs to your parents as soon as you can. If he sleeps late every day, perhaps you can leave in the morning. Could you call your parents to come and help you leave? Lockdown rules don’t apply when you’re escaping from domestic violence so don’t worry about that.
Do NOT tell him what you’re planning. If someone mugged you in the street, you wouldn’t discuss your escape plans with them. Your H is a criminal so treat this in the same light. Plus he is likely to become more dangerous to you if you discuss your plans with him.
If you have time to pack a few things, here’s a list from Women’s Aid website but remember nothing is more important than getting you and your children to safety - supplies can be bought, documents and things can be replaced - you can’t. Get as much RL support as you can and keep posting here also.
Some form of identification
Birth certificates for you and your children.
Passports (including passports for all your children), visas and work permits.
Money, bankbooks, cheque book and credit and debit cards.
Keys for house, car, and place of work. (You could get an extra set of keys cut, and put them in your emergency bag.)
Cards for payment of Child Benefit and any other welfare benefits you are entitled to.
Driving licence (if you have one) and car registration documents, if applicable.
Prescribed medication.
Copies of documents relating to your housing tenure (for example, mortgage details or lease and rental agreements).
Insurance documents, including national insurance number.
Address book.
Family photographs, your diary, jewellery, small items of sentimental value.
Clothing and toiletries for you and your children.
Your children’s favourite small toys.
You should also take any documentation relating to the abuse – e.g. police reports, court orders such as injunctions and restraining orders, and copies of medical records if you have them.