Fps drops

hi so I have been getting low fps since a month or two. my fps goes from ~200-120 to 10-40 fps... i have no idea why and i tried everything that i knew that might help my pc run the game on a decent fps. launch options high priority close anything that is unnecessary updating my drivers (AMD'S and the rest of the computer-driver booster) reinstalling my drivers formatted my pc at least twice cleaned it outside and on the inside a professional to change my bios parameters (it did boost my pc,now i can play 100+ fps for a whole minute!) made my windows look a lot worse so there is less stress using Fps Boosting programs autoexec lowest graphical settings (very low 4:3 1024x768) custom res for my monitor (outside csgo) im starting to feel hopeless and i want to buy a new computer but i think it wont pay off in the long run i have fps drops no matter what (offline,small maps like aim_map,surf,MM maps,community servers...) no ReLive installed Pc and settings: https://imgur.com/a/RN5tu

thanks in advance and sorry for my english.