FPS

what are you computer specs, and what settings are you running at on gmod?

Try making a list of all of the addons installed in your computer currently. It may take a while, but give yourself time, then after you are finished, examine the list and single out the addons you use most often, and proceed to delete everything else.

Otherwise, try to invest in a better computer, as not every computer is built the same, and some work better than others.

Use processor rendering. Install FPS boosters and clear the game and computer. Most likely it will help you

Do you mean your server's fps or your client's fps? Can't help you with the server's fps but you can activate multicore rendering on your client which gives you a huge fps boost.

Garrys mod Have shitting optimalization so on my computer I have 30 to 100 fps

There was an addon called FPS booster i think honestly i never used it since i don't have to

Assuming it isnt your computer, try better addon management.

what are you computer specs, and what settings are you running at on gmod?