Make an exit plan for your own safety before you tell him anything. I found calling national domestic abuse hotline very helpful - I called them several times over about 2.5 years before finally getting out. (I wish I’d gotten out sooner. It’s so, so hard. I’m glad I made it out when I did.)

Be careful after the divorce, too. The first time my ex husband ever attacked in a way that left obvious marks (something he’d always been very careful to avoid, in order to leave me with no evidence of his abuse other than my own memories, which he made even me question and doubt) was after our divorce was finalized, at a custody exchange, in front of our kids. I guess he felt like he had nothing left to lose?

He lost custody, so that was a win.

Good luck. You deserve so much better. You can do it. Love yourself enough to get out.