Before you leave, I'd start setting up a plan without his knowledge to leave. If you have a relative or friend you can trust, you should see if maybe it'd be easier to stay with them for a little while and then file for divorce when you know you're safe. If you ever feel he plans to get physical or starts stalking and so on, get a restraining order (at the very least it allows a paper trail for the courts).
My dad, I knew it was unlikely for him to actually lay his hands on me, though I was entirely convinced a few times in my life "This is it. He's going to kill me." He never did and I had someone and somewhere to escape to. It worked out and helped. You're definitely going to need some support to go through with this.
It's a good thing you're not blind to it anymore because now this means that you can begin working to change it all so that your kids can have a better upbringing. I wish my mom would've done that before I can remember. I think my upbringing would've been a lot different. Granted my mom had her own issues to, but a lot of that was brought on by how my dad treated her.
I'd also keep your therapist thoroughly informed so that it's just more evidence and also good support; that and your therapist could probably offer even better advice.