The short answer
What you're feeling has a name: compassion fatigue. It's not that you stopped caring — it's that caring took everything you had. The fix isn't to push harder. It's to treat your own recovery as part of the job, not a break from it.
You've been absorbing other people's pain, day after day, with no real place to put it down. Research on compassion fatigue — the kind that builds up in helpers, therapists, and caregivers — shows this is a recognized pattern, not a personal flaw. The numbness isn't indifference. It's exhaustion wearing a mask. Your nervous system has been carrying a load it was never meant to carry alone, and it's telling you that now.
Marcus Aurelius wrote that the whole point of showing up for others is that it benefits you too — that doing good and being good are the same thing. But that only works if there's a 'you' still standing. If you've run yourself to empty, you can't do good work. You can't be present. The profession he describes — 'to be good' — requires that you stay in it for the long run, not burn out in one fierce sprint.
This week, pick one small thing that refills you — a walk, a quiet meal, an hour with no one else's problems — and treat it like a work commitment you can't cancel. That's not selfish. That's how you stay in the role. If the numbness feels heavy or is affecting your daily life, it's also worth talking to a counselor or a trusted person outside of work.