Accelerator sticks - sometimes is very, very stiff. Mechanic lubricated it with something but it made no difference. I've had to put foot on brake and ten stomp on the accelerator lately. What to do??

Take it back to the dealer. NOW!! Before it kills you or someone else.

Check the pivot point of the accelerator pedal and lubricate if possible. Check for freyed (broken) wires at the cable ends and check for kinks if you have a cable

See a mechanic. Gas prolly loose or need new clutch if its a standard

the cable from the pedal to the throttle may be worn or rusted inside. It makes it stick and holds tention because it sticks. There's lubrication inside the cable from the manufacturer. When the car heats up it allows free movement. It sounds like, either try and lubricate the cable or replace.

replace your accelerator cable.

I would take your vehical to another mechanic, preferably one who knows what they are talking about. If you vehical is still behaving strangly, you may have been ripped off.

take your car to a qualified machanic ASAP like now you may have a strands broken on the meteal stranded accelarator cable or something bent under the dash above the pedal this can be serious it may get stuck if it does turn the key to the ignition a half click back so the car engines electrical power is taken away but the sterring wheel remains unlocked use e-brake for stopping if stick shift depress clutch first then follow rest of instructions

throttle and linkage are sticking, use silicone lubricant spray , apply to both, manually work the throttle and linkage, re- apply,

My gas petal used to stick on the jeep so i spray up in there on the petal to stop it from sticking ore the brake light woud stay on becuse petal got stuck try some WD40 just dont sray on your petal ok might work

Appears you have a broken or sticking calliper. It is not releasing when you take your foot off the brake.
Remove the wheel in question, and check the springs. Lubricate with penetrating oil, and retry.