Can you try
sudo dpkg --configure -a
Have you checked your sources?
In Software & Updates, is your Download from set to "Main Server?"
Sidenote: The frustration you are feeling is something I think we can all identify with. Years of computer use - and every once in a while, we really just want to go full Hulk and smash everything to pieces.
The only way I have found to navigate it is to focus on each step of trying solutions rather than the problem as a whole. I think it may be because our minds manage things better in less overwhelming portions.