I'm sorry you are in this situation. If I am understanding correctly you are in physical danger of an attacker. A past boyfriend or spouse?
Even when face to face with evil, God can protect you and save you from harm. Pray for Him to hide you. Pray for Him to confuse your enemy. God loves you and wishes to protect you. Pray before, during, and after. I have seen His hand in hiding me while in plain view, confusing the attacker, and sending help.
I'd like to give you a little advice on some small changes you can make that might help keep you safe. I hope you don't mind and I hope something in these words helps you to at least feel safer.
Consider changing your schedule. If he knows you come home or leave home on a certain day and time consider changing your schedule. If you can't at least don't buy groceries during this time. Go out for groceries at a different time or buy smaller amounts so you can carry everything in one or two trips.
Or consider taking things from the car and sitting it in front of the door instead of in and out of the house 3 or 4 times to make trips to the car. Sit the groceries at the door stoop then quickly back to the car for more bags. Then when the car is empty you can move it into the house swiftly with the safety of being near the door. Park as close to the house as you can. Back in and leave the driver door open so you can jump in quickly if you need to. Don't put groceries where they are difficult to get out of the car. Such as the back seat in the very center. Leaving yourself vulnerably when reaching in to get them. Also when putting groceries in the car, put the things that need fridgerated or put in the freezer where you can get it out quickly. Things that need to go in the house and can't spend the night outside in the car. Boxes of dry food like cereal or noodles or canned goods can spend the night in the vehicle but popsicles would cause you more stress if you knew they were melting in the car for hours. So put them where they'll be the first bag out of the car. Sounds like you might already be doing this?
Inform your neighbors of your trouble so they know to call the police if they see him there.
Consider a self defense class. I took one once and they showed me how carry my keys so they are an immediate weapon. They have other little tricks like that to help in a situation. Besides, knowing how to defend yourself gives you a confidence and attackers often avoid people who appear confident.
Do you have a friend who is willing to stay with you for a while?
Also the police here just told me that I don't have to be hurt for it to be assault or battery. That as soon as he even brushes against me it is battery. Like if he were to pull back his fist right before hitting me but it brushes against me or he comes at me and his body brushes against me I can call and they will help. It might be different where you live. I don't know. It's worth checking into and finding out exactly what your rights are and exactly how the police can help. It might make him angry, but you'll have the police there to help and you can't go on living like this. What do they advise at the group meetings to do?
Oh sweety above all just know that you are loved, you are special, you are important and you are in prayers of many here.