OP if I could be there with you and help prepare I would. Just take it step by step.
You don't need to do anything right now. Stop panicking, I know that's hard. Breath in through your nose and out through your mouth. It's ok.
You don't need to bring anything if it puts you at risk. Obviously prescriptions for medication is helpful or the actual medication itself if possible.
Refuge workers are used to women turning up with nothing. Sometimes having just run out of the house and up the road.
They normally have the bare basics in the refuge but here's what to pack:
Identification
Birth certificates for you and your children.
School and medical records, including the telephone numbers of the school and your GP or surgery.
Money, bankbooks, cheque book and credit and debit cards.
Keys for your house, car, and workplace.
Driving licence (if you have one) and car registration documents, if applicable.
Prescribed medication, and vitamin supplements.
Cards or payment books for Child Benefit and any other welfare benefits you are entitled to.
Passports (including passports for all your children if you have them), visas and work permits.
Copies of documents relating to your housing tenure, (for example, mortgage details or lease and rental agreements).
Current unpaid bills.
Insurance documents.
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.
DO NOT take anything if it will put you at risk.
Here's some information on what a refuge is like.