Suddenly low framerate on good gaming computer (That had great framerate).

[MAttyg1]

My computer
Intel i5 4690k
gtx 970
8gb ram
corsair RM 550w
windows 10

has all of a sudden not been able to run the games that i used to be able to run at over 60fps at ultra settings.i now go from 291 frames on CS to 10 and it will keep repeating this, some games i cant play as the frame drop is to constant e.g. rust and arma 3

is there anyway i can fix this?by the way all the drivers are up-to-date

 

[bootcher]

Check your temperatures, it sounds like your CPU/GPU is being throttled, to prevent overheating.