Get back to your dentist ASAP
if the temps do not feel right when biting down and your jaw and teeth are in severe pain you need to have your dentist fully evaluate the situation prior to the ceramic fabrication of your crowns. This may be as simple as a bite adjustment of it may be as complex as the need for root canal treatment. Communication is key. Be sure to bring up all your concerns at your dental visit and be sure you fully understand the situation and possible treatment outcomes going forward prior to your permanents being made up.
There are way too many variables to go into for the cause of your pain. Remember, they are temporaries and many time can be uncomfortable. If severe, schedule an appointment with your dentist to evaluate your bite and make any necessary adjustments.
Temps can be removed and remade easily. The most important problem is that you need to have your bite comfortable and stable before your final restorations are made. I suggest putting your restorations on hold until your dentist can figure out the current problem.