Hello Bsjulstad,
Welcome to this forum.
Sorry to read about the pain you are in.
I would highly recommend that you seek the advice of a spinal surgeon. They are the most knowledgable about spines and back issues. Search for the very best spinal surgeon in your area, and then make an appointment to see that doctor. In fact, make an appointment with the spinal surgeon listed 2nd on your list. A 2nd opinion is always a good idea.
You are very correct, you need to have an X-ray. (You are far ahead of your chiropractor.) Do have the x-ray as directed by the spinal surgeon. I would not put my trust in your GP (PCP) to have it done correctly.
I'm with you on the Flexeril. I tried it once, never again.
I hope all goes well. Let us know how things go for you.
RichT
P.S. - May I be so forward and ask how long you have had your current mattress?