Delete All the folders with folder type.Right click > Select Sort by > Type > Ascending.First Navigate to your Gmod local files then opening.Redundant addons can occur when you are verifying the integrity of your game folders or have had an issue when you have had to download your game or some add-ons. C:\Program Files\Steam\steamapps\Yourusernamehere\garrysmod\garrysmod\scripts Use this folder to insert or delete custom scripts. This Step should only be used if you have played on lots of different servers but have recently started playing exclusively on one. Look in these files and you will find everything you need.
This is downloading the files you need for that specific server. You can't find them because Garry's mod uses the props and textures from other games like Counter-Strike:Source.
This Guide Will show you how to Decrease your Gmod’s File size, It helped me get down about 80gbs, These Tricks will generally only help if you have been playing Gmod for a while or you have lots of add-ons installed.