Tooth extractions are traumatic to both your gums and your bone. The procedure should be considered a minor surgery
. Expectations for healing periods should be viewed through that prism. Having said that it is possible that your hard or soft tissue may not be healing correctly- only a clinical exam by a dentist
can evaluate that for you.
In the best conditions extracting fifteen teeth at once can take anywhere from 4 weeks to 3 months to heal. Each person's body will react differently. I would recommend as many follow up visits with your dentist as you feel are needed- both to manage the swelling/pain and the fit of the denture. As the bone and gum heal they will continue to remodel which will affect how the denture fits.
The symptoms you are experiencing are not unusual. Please follow up with your dentist to make sure your mouth is healing and the prosthesis
is functioning correctly. Feel better.