My honda accord is giving me a high RPM code P0507(Idle Control System RPM Higher Than Expected),however when idle the rpm is slightly below 1rpm on the guage, but speeds fast when brakes are released, please find explanation below:

The car has a normal low rpm below 1rpm when car is Idle on the rpm guage, however when driving(Gear on D) and i realease my foot from the brake pedal without steeping on the accelarator, car moves at a high speed by itself and almost initates into second gear all by itself without stepping on gas.

Another thing i noticed is if i'm speeding like 60mph which could be 3rpm on the rpm meter and i remove my foot from the accelerator without pressing the brake, car keeps maintaining that speed for sometime instead of decelerating automatically.

Please help as this has been affecting the way my transmission shifts as it doesnt shift smoothly due to this error.

Is there anywhere that i can control this high rpm, please note as explained that the rpm meter guage is below1 when idle.