I'd already given him an ultimatum that if he did (the thing that pushed me to divorce him) one more time, and failed to seek help for himself, that it was over, I was done. We saw, at his suggestion, a couples therapist about four times, which had the effect on me of seeing he would never change if he did not wish to change ("l'm not that bad" and "lots of couples have far worse issues than we do" were said by him, and the therapist said privately to me "he's an 'interesting' guy...")
So, when proof of the thing being done again came, I said we're done. He heard but didn't hear. We attended the counseling, which helped me see he would never change. I made plans to find an attorney. He ignored the situation, then asked soon after (like nothing had been said) if I wanted to go out to eat, just he and I, not the kids. I said only if we can talk. He said sure, but acted like he didn't know what I was talking about, what did we need to talk about?
We went out, ordered our food, I told him directly that I do not wish any longer to live with you, you've done the thing again, obviously you will continue on as you have been and for this and other ongoing examples of disrespect to me and our kids, I will be finding an attorney and working out what to do next.
He was still in total shock. Total denial. I was glad I laid it out in a restaurant, in public. Glad a band was playing so the scene he created was sort of muffled. 😬 He kept saying "you think I'm that bad?" Over and over. I had to keep saying it was over, we really are done, I'm really going through with it. I think he never ever thought I'd have the guts to do it, that there would never be consequences for his behavior.
One word of advice, if you have kids. I did not warn him not to speak to the kids until we'd worked out how to tell them, so the minute we walked in the door back home, because he looked so defeated and upset, one child asked what was wrong, and he blurted out to them "well it looks like your mother and I are splitting up".
Kids took it very hard, thanks in part to his behavior.
He went into pity mode and still couldn't believe I was actually going through with it. Then turned very nasty and found his own attorney that does collaborative divorces and insisted that I use that law firm instead of the attorney I had already decided on, threw another fit when I calmly said no, I have my own attorney, and I have an appt next week, and I intend to have her file. Then became very angry that I would dare hire my own attorney rather than do the divorce at his dictation, then tried to one-up me by trying to get his law office to file first...I said go right ahead.....anyway, it all made me absolutely sure that I was doing the right thing to divorce him.
My atty and I did end up filing first. I guess the thought for my H that whomever filed would have to pay the filing fee changed his mind!
Good luck to you. Get all your statements and accounts and taxes printed out beforehand. First steps in the proceedings are a huge stack of paperwork of financial information. Make sure you have access to everything.
One step at a time.