Synaptic Package Manager

[ralphy]

Ok, let's give it a good go and luckily this should bring your system back to normal.

1- Run in terminal:

sudo apt-get clean
sudo apt-get autoclean -y && sudo apt-get autoremove -y

2- Download the zip file below, unzip it and install each package in the order listed starting with #1 (these are 64 bit)

https://unlockforus.com/downloads/linuxlite/debs.zip

3- Reboot the computer

Note: You shouldn't usually download deb files from unknown sources and install them but since you can't download packages this is the only way I can get the right versions to you.

Let us know how that goes. Cheers!