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

You became the grounds lead. Now you manage a crew and a budget instead of doing the hands-on work that let you look back at the end of a day and see exactly what you had done. That visible, finished result is a real thing to miss, and missing it does not mean you took the wrong job. There is a particular satisfaction in physical work: the ground was rough this morning, and now it is right, and you did that. Management rarely gives you that clean line. Your wins are slower, spread across other people, and harder to point at. Losing that daily sense of I made this is a genuine trade, and it is fair to grieve it. But you have not lost the ability to see what you build; you just have to look wider. The crew that runs well, the young worker you taught, the whole grounds kept right across a season, that is your work now, even if no single afternoon shows it. Learn to see it. And keep your hands in the dirt sometimes; do a task yourself now and then to feed that part of you. Pick one this week. You can lead the crew and still be someone who works the ground.