Throttle bore service?

Hi. I have a serious problem right now. When I remove my foot from the gas pedal, the car continue to accelerate. The gas pedal doesn't get stuck but speed keeps increasing. When I press the brake it only maintains the speed. It does not slow down my car and it does not even stop it. I can only drive at 40km/h and press the brake pedal to maintain that speed. I don't know what else to do.