Multiplayer error

i can play singleplayer fine but when i go in multiplayer my eye height is halfway in the floor other players are invisable and it just happens on every single server it hasnt gone away.i have tried defragging and all that but people say i should re install i dont wanna do that because i have stuff i have downloaded that would take like a solid week to find again
PLEASE HELP its really ****ing annoying not being able to play my favorite servers

You don’t have to delete your addons. Just create a new folder or rename the old.

You **should TRY ** to reinstall with no addons, then move the addons back.