How do I play back while recording?

When I have a click track in audacity, and I’m recording other tracks over it, how do I do that without the overdubbing? Overdubbing causes everything to become ugly, distorted, messed up, and mushy, but i cant record into audacity without everything synced to the metronome or else it does not sound good. Any help is greatly appreciated, thank you!

Overdubbing should be enabled (Transport menu).
Software Playthrough should be disabled (Transport menu).
Ensure that Audacity is set to record directly from the line/microphone (whichever you are using) and not from “Stereo Mix”.

This set of tutorials from the 2.0 manual should help you: