Hi, I know exactly how you feel. I recently ( last month) had all upper & lower teeth removed due to poor care. For me the upper plate is the only one I am comfortable with. The lower unfortunately is very loose and I havent been wearing it. It take a long time to get used to having this new "object" in your mouth but, the more I wear it the better it seems to feel. It's a long process but you will get thru it I promise.
Make an appointment with your dentist and have them check the denture to make sure it's fitting properly. Sometimes just a few minor adjustments will make all the difference in the world about how it feels in your mouth.
I will be more than happy to answer any other questions you might have.
you are not alone.