Thank you for your question and I understand your concern. Without having the model number of your range the only instructions I can recommend trying is to program the oven control for another self cleaning cycle and start it, wait 1 minute and then press Cancel/Clear/OFF and wait to see if the door lock mechanism will release the door. You also may to push in slightly on the door when Cancel/Clear/Off is pushed and see if it unlocks.
If the door will not unlock, I recommend calling and setting up a service appointment to have your range repaired.
You can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services