Gas pedal acting screwy?

I own an 87 5.0 fox (5 speed), and I decided to get on it a bit when a 03 Mustang dared me haha. Almost immediately after our little show my gas pedal started acting a bit funny. Now there is no best way to explain this, so I'm going to try. After all of that nonsense, and ever since... my pedal has had a huge response change, I would lay my foot on it, applying slim to no pressure on the pedal and my car would accelerate quite quickly. The pedal seems to be at the right height as it usually is, but it has a very small change of stiffness, it becomes a little too "loose." By pressing the whole pedal to the floor, it's loose for maybe a half inch? After that it feels as stiff as it should be, maybe a little stiffer? But nothing huge and drastic, just how much acceleration I have lol. Then about a minute later it will return to normal and I can rest my foot on the pedal without any acceleration. Then again it will return back to being a pest. As you would imagine when it decides to switch itself (or whatever it's doing) back to a more responsive touch it makes it hard for me to shift or even drive for that matter. I can't figure out what is happening; I don't even know what causes it to happen. I'm starting to believe that it only happens when I push the pedal a little harder, but still not sure because it doesn't happen all of the time.

I'm asking if anyone has any advice on what to check and how, I’m open to all suggestions. I just want to drive normal again haha.

If you have any questions about my story or what exactly happens, I'll be happy to try to expand a little more, to make it a bit clearer. Until then I'll be looking around trying to find the problem. Thank you all for your time and suggestions if you have them.

Could that also be why within time, I'll have to adjust my idle to keep a steady charge in my car.

If it were that sensor, would it really mess with how my pedal feels? It does feel different, enough to notice the change.