To confirm the issue have your mechanic replace the TPS with any used one that is working and see if the jerking is still there when accelerating at low rpm like 1000-1500 rpm. Another symptom that could signal a TPS issue would be the engine RPM dipping too much when the radiator fan kicks in. But do ensure that the IAC valve has been cleaned and is rotating freely first to rule out any issue due to it.
Don't try to repair the TPS, it won't be worth it. If you determine that TPS is faulty replace with a used but working one. I don't think new ones are available. Even if new were available they would cost too much
