Because it's not always as simple as "just dump him" or "just leave him". When you already moved in together and have a lease, or if you're married already and have a house or kids it's not that simple as just packing a bag and vanishing.
What you can do now is start making an exit plan.
If you're living together and in a lease: you need to evaluate yourself and go over the lease terms. Where us the lease? If you can't find it you can obtain a copy from the landlord or office. First of all, make sure you're on the lease. If you aren't on it, then you really can pack up and leave. If you are on it, see when it ends and what the move out process /breaking the lease process would be. Each lease has its own rules and same with each state.
You need to make sure you're committed to leaving him. Make a plan and follow it through ensuring you're safe and the timing is right. If you flip flop and keep running back to him he will know what's up and make it harder for you to actually leave.
Now that you know what the lease is like and that you're committed to leaving, start looking for somewhere else you can go. Can you stay with friends or family? Can you get a different apartment lined up? Where are you financially?
I was in a lease with a bad roomate before and her on again off again scrote. I waited it out until the lease ended: otherwise I would have had to pay the remaining rent or could have been sued. During that time, I slowly started downsizing what I had. Because it was gradual she didn't even realize how much I had gotten rid of. I did mention to them I wouldn't be renewing but they started to freak out and get emotional and vindictive. So i didn't mention it again and slowly started saving up money and downsizing. She'd use my items or steal them. So I got a storage unit and also slowly started putting my items I cared about the most in there.
I lined up another place. As it got closer to move out Day, when she was working I grabbed what was left of my stuff and moved it out before she came home. All the valuables and items I cared about were already in the storage unit. I had done this a month before the lease was ending. I had another place lined up and had Gotten the keys.
But with a scrote sneaking yoir stuff out when he's at work and having it in another location like your parents house a storage unit or if you already have another place leave it there. I made sure not to fuss too much over furniture I shared or contributed financially too - I was fine woth cutting my loss. It was more important to leave safely and quickly.
When I was biding my time I kept busy, did my own thing, and kept my door shut. Whenever they'd notice i said I was working or doing something for work. Pulling away slowly but steadily is key.