Womens aid have some great packs on leaving safely as do the police. I kept a suitcase at my dads with a credit card and clothes for me and my kids. I told X that he had to leave with relate counsellor there to protect me and then had my dad stay the night for some time until I was sure I was more safe.
In the end the police put an alarm in my house but my local refuge had said they would help if need be.
All of the evidence though on DV shows that men usually get worse when the woman leaves or stops the relationship and most women who are murdered as a result get murdered after divorce or just as it is about to happen.
These type of men hate to loas control.