Hi lawoffice474...
Unplug your foot pad from the machine and the electrical receptical.
Try moving the foot pedal with your hands, back and forth as if you were pressing your foot on it.
Did it loosen up?
If yes then you still need some maintenance...
If no then you still need some maintenance.
Disassemble the foot pedal and take as many pictures as you need to be able to reassemble it.
Once you have disassembled then you will look to oil (one drop max) the pivot points of the foot pedal, like the hinge assembly, reostat linkage,etc.
Once you have it oiled then try moving the foot pedal again my hand before reassembly.
If everything moves ok then your good to go...
Reassemble the foot control.
If not then its time to replace it with another foot pedal such as one of these at this webpage below:
Please take time to rate me thumbs up.
http://www.sewingmachinesplus.com/singer-foot-controls.php