[8FS_Bulau]

... i want it so it increases and decreases ie i push up and it throttles up and when i go back to the center it stays at that throttle until i lower the throttle by pushing the stick down

If the controller acts as a keypress or joystick button, rather than an axis, you could set it up that way, so that a push forwards sends an "increase throttle" keypress, and vice versa, by mapping those in IL-2 to "Increase Engine Power" and "Decrease Engine Power".

If it only works as an axis, then you won't be able to do what you want. I reiterate my earlier advice...get a real joystick which has a proper throttle axis on it. Even a crappy one will be better than a PS controller.