Does Degenerative Disc Disease Cause Pain On Sitting For Long?

The last few weeks I have had a lot of pain if I sit in a car for more then 15 minutes it feels like there isn't enough room for my rib cage the last few nights I have had trouble sleeping. My normal position is on my right side with my left knee pulled up and lying on a pillow. Last night I realized my ribs and hip bone were rubbing together. I have degenerative disk and hip bones is this just a normal progression of that or do I need to see a dr. My family dr. has said it is just normal aging and I will have to just deal with it. I am only 44 and can't imagine what 54 will feel like if I am already having this much trouble