Hi @watchpocket ,
are you using Gdebi to install the packages?, if you download a .deb package and open it with Gdebi it should resolve the dependency Problems for you!.
You can also search for missing packages here:
https://pkgs.org/
Try changing your Software sources download Location as well, see the update guide:
These are my own setting preferences, use at your own risk!.
AN IMPORTANT NOTE FOR LINUX BEGINNERS. WHEN YOU ARE IN RECOVERY MODE, THE KEYBOARD DEFAULTS TO US ENGLISH, IF YOU HAVE ANY OTHER LANGUAGE KEYBOARD OTHER THAN US ENGLISH, WHEN YOU TYPE "Y" (FOR "YES"), IT MIGHT SHOW UP AS A DIFFERENT LETTER, ON MY KEYBOARD I MUST PRESS THE "Z" KEY WHICH EQUATES TO "Y" AS I HAVE A GERMAN KEYBOARD, JUST PRESS "BACKSPACE" AND HIT A DIFFERENT KEY UNTIL YOU SEE THE "Y" SHOW UP!.