89 Thunderbird Fast Idle

I'm having trouble with my idle as soon as I turn the car on my rpms increase right on start up and will not slow down if I drive the car I will build up speed until I hit 35 then the rpms fall really low and I half to give it a lot of gas then when I hit 45 the rpms increase really high and I accelerate without having to hit the gas and when I get to 55 the rpms decrease again causing me to half to give it more gas thus I'm having a shake bomb throughout my car when the rpms are down and the brake sticks and its really hard to slow down the rpms are high what should I do and was told it was the speed control idle but not sure any suggestions?