Take a look at the Flywheel Help doc on this:
How to uninstall on MAC?
Stuck on "Starting Local Machine"
Installation blocked at third step (Local Image)
Local Crashed and Now Won't Install After Uninstall
The Site Can't Be Reached
Updated to 2.4.3 Now hangs on checking system
Resolved - Remove SSL Redirects
None of my sites start after upgrading to 2.3.2 from 2.3.x Pre-release