By any chance did you rename your network interface? We are assuming you are using the default name of Wi-Fi. Try running this command:
networksetup -listallnetworkservices
Do you see Wi-Fi listed?
Next, if you really think the network settings are a mess, and you can easily recreate everything, you can trash the network config plist, reboot, and start over. The file you want to trash is:
/Library/Preferences/SystemConfiguration/NetworkInterfaces.plist
Save all you work, move that file to the Trash and immediately reboot the machine. On reboot, the system will poll the available hardware and reconstruct the NetworkInterfaces.plist file.
Hope this helps