How do I adjust to managing people instead of doing the work?

You made MD. Now the job is managing juniors and clients instead of building the models you were the best at. That is a strange summit to reach, rewarded for your technical skill by being pulled away from using it. Missing the work itself is not weakness. It is the honest feeling of someone who loved the craft, not just the title. The modeling was yours in a way management is not. You knew exactly what you were making and how good it was. Now your value comes through other people's work and relationships you manage rather than execute, and it can feel less concrete, harder to grip. That shift from doing the best work to overseeing it is one of the hardest in the whole career. Feeling it is normal. Your job now is to build sharp juniors and steady client trust, a different craft, and one your deep technical judgment makes you good at. You can tell great work from sloppy work instantly; use that to raise the people under you rather than redoing their models. Coach, do not just correct. And keep a hand in a few analyses to stay sharp. Pick one junior to truly develop this year. Leading well is spending your skill through others, not losing it.