my milwaukee m18 drill is making a weird grinding noise when i use it, did i break it?

Grinding noise indicates a mechanical failure inside the gearbox or chuck. Stop using it immediately.

Fix:

1. Remove the battery.
2. Inspect the chuck. Try tightening and loosening it by hand. Does it feel gritty or loose?
3. Spin the chuck by hand. Grinding or resistance points to internal damage.

If that didn't work, the issue is internal. This is not a user-serviceable repair.

Heads up: Forcing the drill when a bit is jammed, or using it with a damaged accessory, can cause this. The tool needs professional service. Check your warranty.