When Daddy's Discipline Went Too Far

I'm a grad-school dropout turned Mommy for my boyfriend Alex. We started playing DD/lg when I was in my mid-twenties, and it brought us closer than ever before. It wasn't just about the physical stuff; it was emotional too. The way he looked at me, how he spoke to me, everything felt so right and real. We had a solid routine of role-playing for a few months. I would be his mommy, take care of him, tell him what to do, sometimes give him little punishments like time-outs or grounding. He loved it too, acted all submissive, cute as can be. Then one day he wanted more than just light discipline. He said he needed me to push the limits. To really show him who's boss, make him feel small and weak in a way that only I could. I was hesitant at first but Alex convinced me we had trust and safety between us. So, okay. We started with spankings and belt swats. Then he wanted harder stuff like slapping, pinching, even biting the back of my neck to make me squirm. He called it 'breaking me' and I let him because I thought that was what we were both into now. But then one night he went too far. He told me to kneel at his feet in front of friends, to beg for forgiveness while he spat on my face, calling me a bad girl, demanding I take off my clothes completely there and then. It turned everyone else on seeing this 'weak' side of me but it made me feel sick inside. I left the room that night feeling used and dirty. I couldn't shake the shame or resentment after that. Alex tried to say it was all role-play, no real harm done, we were consenting adults. But something shifted between us after that. He kept pushing for more 'extreme' stuff but I felt violated. I'm not sure if this is normal in DDLG? Or am I being too sensitive? We still play, just less now and way softer than before. But every time we do he seems to want me back there - in that dark place again. Should I talk more boundaries? Leave the dynamic altogether? Help.