did you actually go into your folders in your computer to make sure they were removed?
rundown of what you should do:
-unsubscribe from all your addons from the gmod workshop if all of your gmod addons are for tnb, if not just remove all the tnb addons
-go into your gmod properties on steam and head to your local files then browse them, i think it's garrysmod/garrysmod to take you where you need to go from there
-go into your addons and servers files and delete everything from there, the addons are from what you've downloaded from the workshop and the servers folder is files downloaded from servers (fastdl)
-go back to the workshop and download tnb stuff again, launch up gmod so they install fully. don't go into any servers, stay in the main menu while they install
-after they're all installed, restart gmod and if you're wanting to feel safe, verify cache before restarting gmod
-hop on a server and see if it worked