Terrified. Please reassure me

I have experience and he’s likely to seriously harm you.

You are in danger. Your child is in danger. Call the police.

If you called the police and they took him to the station, it’s likely a non molestation or no contact order would be made by the court.
If he broke that then that would give you more evidence for court re contact.

If you think it’s likely he would break the order, talk to your landlord, if it’s a rented property, about changing the locks. Yours and your baby’s safety is paramount.
I don’t know where you would stand legally on him not having a key though.

Edited to add just seen your post re mortgage, but advice still stands.

If you are able, get some documents together tonight so you have them in case you need to leave quickly.

Could you pack a bag for you and the baby and leave it in your car if you have one?

Are you able to take any photos of the damages? Keep it as evidence. Obviously only take photos if it is safe to do so and he’s unaware.

Please keep as safe as possible. Only gather important necessities, bank cards, documents, birth certificates and passport.

Op can make an emergency application to court for an occupation order and that can be heard within a few days.

You can do this.

Quietly get what you need together, pick up your child and leave as soon as you can, tonight if possible.

Once you're in a safe place, call the police and tell them everything. Try and talk to a female officer specialising in domestic violence. Stand your ground and make sure you're heard.

It will be ok.

He can retain key but you can lock from inside put chain on and call 999 if he theatening and banging on door

You can change locks and "forget" to pass on his key until he goes to court for it

So sorry you are going through this. Please please ring the National Centre for Domestic Violence helpline. They can help you apply for a non-molestation order which will send a clear message that if he approaches you again, police will be the next step. They can help with an occupation order as well. Have you still got a health visitor? Please speak to them about getting an IDVA (independent domestic violence advocate) who can help guide you through this. Women’s Aid are good too. Stay strong and good luck.

Does he have a court order for his access to his older children? Just curious if he had to fight for access or not.

Do you have any friends or family far far away? Would you consider moving far far away? Because if you could I'd seriously consider it.

Please report
smashed it to pieces, broke furniture and punched a hole in the wall, whilst screaming insults and threats at me.

Potentially he can be cautioned by police to keep away giving you time fiorlegal wats
If you do not report now you have zero evidence

I have some experience in this area.

There’s no point just telling the GP although you should tell them, you need to report to the police and press charges I think. I understand the situation you are in, it is not as simple as just leaving, however given what you’ve said I think even tho leaving is complicated you still need to do it. Can you move reasonable distance away to a support network so that contact becomes expensive and difficult for him?
if you can do so, I would do it now before court get involved (if they do, are you sure he will
pursue this?)
take photos of damage, get whatever evidence you can as you may need it.
Will contact fall apart with the other 3 kids without you there? Is there any kind of paper trail showing that he has not met their needs or is a safeguarding concern? This may help you if you have to persuade a judge.
the family court system is so unbelievably fucked up, I really do understand your concern.

He’s putting his older dc in danger too. Drink driving with them in the car? Where is their mother in this? Is she aware? Sorry I know your main priority right now if your baby and your safety but he sounds like a liability for everyone.

Court is a long and expensive process. Would he bother with it if he’s not that interested in his baby? I’d get out, block his number, get all the advice and evidence you can and wait and see if he even follows it up.

Please contact Women’s Aid and see if they offer refuge accommodation. Even short term until you can get him out the house. Just take what you need for you and baby. Contact social work and advise them if you have fears for his older children’s safety if you are not there. He could kill his kids or someone else by drink driving

I really wouldn’t usually say this but. Disappear. Run very far away from this man.

How far away is your closest family and can you go there. First and foremost get you and your child to safety. After that raise the safeguarding concerns. Get to safety and take everything from there

I totally understand that you want to be there for your baby and protect her but, if he turns on you, who will protect her then?
I was about to post this before you said you thought it had almost got to that point and I’m afraid it’s only a matter of time; You’ve got to get away NOW!

The younger your child is when you get out the less likely it is he will get overnight/weekends.

The older your child is the more he will play up the bond he has with her and her suitability for overnights/unsupervised.

The best you can hope for is to leave now, make it hard for him and hope the novelty of terrorising you both wears off before hes established any sort of relationship to demonstrate turning up, being on time, etc.

I get why you think your child will be safer if you stay, but if you stay they will continue to be exposed to violence and unhappiness which they will become more and more aware of as they get older (and the violence and control is likely to escalate). That will cause them damage - I don't say that to make you feel bad, just to provide a counter-balance to the thought your child will be safer if you stay.

You and your child deserve to be safe and happy. I think you should trust the advice of the helplines you've spoken to and make plans to leave safely and take out the non-molestation order. I'm sorry you're in this situation.

Police evidence will very much help you with court processes and it is reasonable you would be asked why you didn’t contact the police if it was that bad. I completely understand your reasons and you are right to appraise the risk he’d pose if you did. What did the domestic violence helpline advise you re police?

If something happens to you, he'll be left holding the baby with no one to protect her. Leave as soon as you can.