What does it mean that I can take abuse at work without flinching?

You have gotten good at absorbing abuse without reacting, and now that skill scares you a little. That fear is worth listening to. It means you have not actually gone numb — you have just built a shield so thick you have started to wonder what is left underneath it. Taking the abuse without flinching kept you safe and let you do your job. It was a smart adaptation, not a defect. But there is a difference between not reacting and not feeling. The first is a boundary. The second is a slow erosion. What you are sensing is that you may have drifted from one toward the other, and you would like to make sure you can still feel. You can. Off the clock, check in with yourself: that thing they said today, did it land? Say out loud, even alone, that it was not okay, so your mind keeps knowing the difference between calm and surrender. Keep the shield for the shift. Take it off when you go home. The fact that you are asking this question is proof the real you is still very much there.