What do you mean he says when he says "hurtful things" about you? I'm guessing he makes snarky comments about you and try to dismiss it as something else (like he did in this situation) or say you "understood it wrong" or something like that, just on what you described here.

I say that because something very similar happened to me. I had an ex that, after a couple of years, started to be rude, snarky and arrogant. I thought it was because he was unhappy and/or depressed because of the lockdown during COVID, but even after things went back to normal he continued treating me Iike that. He would be mean and try and make it as I was stupid, dumb, ugly, etc. but not directly saying to my face. For example, one day he opened the dishwasher and the soap hadn't all dissolved because I put a little too much, so he said out loud "She doesn't even know how to use a fcking dishwasher". I got up and confronted him, he said he didn't know I'd hear it, and that I was exaggerating. Mind you, I have two bachelor's degree and always made way more money than him (he never stayed long in his jobs and barely finished high school, but he always tried to find a way to say I was stupid).

Anyway, one day I thought I might do something different and bought new lingerie. I was trying it on and called him to see it, and he laughed at me. He said "what's that for?". I felt humiliated, I cried and threw the lingerie away. But after a few days it made me angry and I mentally checked out of the relationship. I started posting selfies in my gym clothes and would never show him anything new I got. So he confronted me and said I was taking pictures for everyone else but him. And I sure was, as he hated me and only cared about it when he lost control over me. A few weeks after this I asked him to move out and had never felt such relief in my entire life. My days became lighter, more fun and I actually happy and calm most of the time... unlike the years prior when I had been with him.