In the case of a stuck accelerator, the correct thing to do is to immediately PUT THE VEHICLE IN NEUTRAL.
The engine will continue to rev hideously but don't let the noise panic you; IGNORE THE NOISE- you will be able to come to a controlled stop in a safe place.
Do NOT turn off the key; repeat- DO NOT turn off the key as you will lose power assist to brakes and steering.
Put the transmission in neutral.
If the accelerator sticks, put the transmission in neutral. Repeat this to yourself over and over until you internalize it