If you just had the extractions done at the same time then you are experiencing just an overwhelming amount of trauma etc. It takes time to adapt to wearing a denture. Try putting a small piece of hard candy in your mouth and sucking on it, something like a tic tac. It works well.

Also do not be shy about going back to the dentist for adjustments. Make them aware of the sensations you are experiencing. They can make adjustments easily.

Good luck