No pedal response, or slow acceleration

I am in dire need of assistance with diagnosing a strange symptom (my car is the coupe model) is doing.

It all started on a drive to Utah from Arizona. We were going up an incline and got cut off by another car and had to push on the brakes. Upon trying to resume accelerating, we got no response from the gas pedal. Nothing at all, besides a slight acceleration until we pulled off the road. I could push the pedal to the floor with little to no response, and mostly no response. I turn the car off for a few minutes, started it up, and we were somewhat back to normal. It accelerated, but did not have power behind it. It took much more to get to eighty mph, or even sixty mph.

But then, it would drive fine. For two days, it ran fine without incident. But on the drive home after a couple hours, I had it in cruise control, and heading up a hill it just kicked me out of cruise, and when I hit the pedal I got no response. Though it did not slow down as if I removed my foot from the pedal, it slowly dropped mph until we pulled off again. If we turned the car off for a few minutes it would return to working (though seemed to have lag in throttle.). It did it a few times more. Today during local driving it just seems to have a lack of response and throttle, taking more effort to accelerate.

It may have started a few days before the trip my girlfriend said (it is her car), as she said it did the symptom of not accelerating as fast as normal.

Reading about the symptoms of low fuel pressure, it does not sound like it. The car never sputters, jerks, or has any other symptom besides no response when the gas pedal is pressed. The engine runs sound, and idles perfectly. We drove at least three hundred miles before it happened on the way back, the first time.

My initial thoughts are the throttle body, or some sensor or electoral component. But, I am not even remotely comfortable with diagnosing mechanics.

Actually one other thing to add, when it does this, and right before it revs to over three thousand rpm's, and sometimes past four thousand before it stops responding at all. That is the case also when it has a hard time accelerating.

Any and all help is appreciated! Thanks in advance!