I would not exactly define it as strength, but there was an urge, something that simply had to be done. My ex was also emotionally and verbally abusive . And things started rolling, step by step.
First I moved out, but I was hoping deep down inside that he would just say "Please stay, we can work things out." Of course that did not happen. I set a very firm boundary, with myself only and it was, "If he comes to my new place under the influence, I am divorcing him." You know that right now I cannot even remember how I told him I was to divorce him? I know I went to see an attorney, and we talked, and the guy told me how much it would cost, and I was about to suffocate holding back tears and told him that I would be back tomorrow: "I have to talk to my husband." And the husband was like "Sure, fine, whatever, just show me where to sign." I know I was crying a lot that day, like every 15 minutes or so, woke up at 2 am, and cried and cried, but I kept telling myself "You gotta do it." I remember going back to the office, giving my credit card to the secretary. It was a quicky, emergency divorce because I asked for absolutely nothing.
I feel no guilt, because of what happened after. He started ending up in ER almost every month, accumulated huge debt, and the last thing I know is that he lost his job, and is now back at his mom's. So, you can say I got the closure.
I've been divorced for 18 months, single but happy, living my life the way I wanna live it, substance abuse and drama free.
It takes one step at a time. It really does. And let go, and let God.