I have to use force on the accelerator while stopped
 

Unhook accelerator cable at throttle body. Rotate throttle to check for binding. If no binding then the issue is in the cable between the throttle body and accelerator pedal. Check for kinks in this cable. If no kinks then expect to find corrosion inside the cable. Remove cable, verify corrosion and binding exists and replace cable. Imagine what would happen if the cable stuck with the engine running at 3000-4000 RPM.

Something similar happened to me on a completely different car about 20 years ago. It had a manual cable assist for the cruse control, married up to the throttle underneath the pedal cable. The exterior stiff plastic had cracked and when I was stepping on the pedal, the Cruse cable was bending and binding the whole process...same feeling you described...had to put a lot of physical force. I was fortunate to have tie straps in the car, and formulated a rig fix until the cruse cable I ordered from the dealership came in. Was like a $30 part back in the day. Not saying yours is a cruse cable, but as Doug above stated, you may have a bound up cable...