I spent 18 years being abused. The below was sent to me
The reason you won't leave is called "Cycle of Abuse".
Abusive men are usually quite charming, narcissistic and manipulative. When he's not hurting you he's probably a very nice guy and you might even think to yourself: "I'm really lucky to be married to such a wonderful person. If things get ugly sometimes it must be something I'm doing. If only I could get it right none of this would be happening..." but no matter what you do, all of a sudden he seems to be upset with you for some reason and you don't know exactly why.
Since you assume it is your fault you then begin doing things to "appease" him. This is when the abuser feels most comfortable. He is in control! ... But something, sooner or later, no matter what you do, causes the abuser to snap: Maybe the house wasn't clean enough. Maybe you weren't home on time. Maybe you wanted to watch the game. Maybe you didn't do what you were supposed to do and then comes the actual physical, emotional and verbal abuse for which you feel responsible.
Now, if he were abusing you all the time then it would be easy for you to leave him but after the "explosion" phase comes the reconciliation. He becomes sweet, kind and apologetic. He will say and do anything so your relationship will go back to "phase 1" where he is once again in control of you.
However, you must understand something . The cycle of abuse is like alcoholism. It will keep escalating until you decide to quit with all it's painful consequences or continue drinking until you die. There's no other choice, and the same applies to authentically abusive relationships like yours.
If you have already started documenting the physical abuse he has perpetrated on you, this means you already know there is a good possibility he might kill you and you want to leave proof of his guilt. You're not preparing a case for divorce. You're recording the road to your own demise.
you have to leave, for your sake and his. If he goes overboard one of these days you'll end up dead, he'll end up in prison and what will become of your children, if you have them?
I won't lie to you. Leaving him will be the most dangerous and treacherous part of the journey. He might begin stalking you or his violent behavior might escalate and I only wish I were there to lend my personal support, but since I'm not, you have to find your own support base: friends, family a battered woman's shelter..... whatever! Seek and you shall find.