adobe reinstall - cannot find archive

I have tried to purge my system of 'extra' plugins that I suspected were stopping flash from working and reinstall adobe flash. In the process an error sign popped up: 'The package 'adobe-flashplugin' is in an inconsistent state and needs to be reinstalled but no archive can be found for it.'

It said to go to package manager but if I try to open up synaptic package manager I get the same message and also: 'internal error opening cache (1).'

Attempting to remove or reinstall through terminal just results in the same message - E: The package adobe-flashplugin needs to be reinstalled, but I can't find an archive for it.

I thought computer janitor might remove adobe so I could reinstall but when it tries to do so another error message pops up: 'E:sub-process /usr/bin/dpkg returned an error code (1)'

Update manager also won't seem to do anything until the problem is resolved but my attempts at both reinstalling and removing the flash plugin have been unsuccessful. Is this a bug? A corrupted file? Something else? I know it was probably my own screw-up somewhere along the 'remove/reinstall' process but I feel like I'm going round in circles trying to solve this! Please help!