Boyfriend punched me for the first time

I don’t even know where to begin.
I’ve (28F) been with my boyfriend (27M) for almost 12 years. We started dating when I was 16. Over the years, I’ve come to realize that our relationship has been filled with cycles of emotional abuse, constant insults, silent treatment, and never-ending arguments that are never truly resolved.
Whenever we have a major fight, he’ll say the cruelest things imaginable. He’ll tell me how much he hates me, that he wants to leave, that I’m a failure, and a million other things that cut incredibly deep. Then afterward, he’ll go days or even weeks barely speaking to me. There is never an apology, never accountability, and never any real conversation about what happened.
A little over a week ago, we were eating dinner together. I had been holding in so much pain from an argument we had a couple of weeks earlier. During that fight, he said some truly awful things to me, and I couldn’t stop thinking about them.
While we were eating, I suddenly started crying. He asked me what was wrong. I initially told him I didn’t want to talk about it because I knew it would probably turn into another argument. He asked again, so I finally told him the truth.
I told him that I was still hurt by our last fight. I told him that I struggle to believe the loving things he says because they don’t match the horrible things he says when he’s angry. I told him that I can’t mentally handle the constant ups and downs anymore, the insults, the silent treatment, and the emotional whiplash.
He responded by saying that of course he loves me, otherwise he wouldn’t do certain things for me.
I told him that actions like weeks of silence and cruel insults make it difficult for me to feel loved.
The moment the conversation became uncomfortable for him, he got annoyed, stood up, and started walking away.
I was shocked because he had just asked me what was wrong. He asked me to open up, and then the second I explained how much he had hurt me, he couldn’t even stay and listen.
Things escalated from there.
I was sitting on the couch when I saw him coming toward me. I immediately put my arms over my head.
He climbed onto the couch and started punching me multiple times. At some point, he knocked me to the floor and kneed me in the hip. While I was on the ground, he almost kicked me in the face, but I turned my head away in time.
What I can’t wrap my head around is the complete lack of remorse.
He asked me what was wrong.
I told him I was hurt by the things he had done.
And his response was to do something even worse.
I genuinely don’t understand how someone can hear the person they supposedly love say, “You hurt me,” and then respond by hurting them even more.
Has anyone else been through something like this? How did you finally accept that the person you loved wasn’t going to change?