Multiplayer is breaking

So one day I was playing GMod like normal when one of my friends messaged me to get a server up, so I quit the game and started a two player server. As soon as the map loaded up, every single one of my addons had script erros, I couldn’t open the Q or any other menus and the costume hands weren’t loading in. I’ve been searching online for the past week on how to fix this problem only to find nothing on the issue. I really need help with this because I can’t play multiplayer with my friends because of it. Thanks for replying!

(This is really broken)