24 and falling apart-literally

I recently turned 24 years old and with a birthday came another surgery.  Right before I turned 21 I was diagnosed with Dengenerative Disc Disease.  Since then I've had 4 fusions.  The first was an anterior and posterior fusion, disc replacement surgery for my L4-5 and L5-6 discs (I have an extra vertebrae).  Since this surgery I've not had one single issue with my lower back!!  The third surgery was my cervical disc C5-6 which came just over a year later.  I woke up from this surgery and knew something wasn't right.  I spent the next year and half trying to convince my doctor that something else wasn't right.  Finally 7 weeks ago they went back in and fused and replaced my C4-5 disc, in which my doctor came out of surgery and simply apologized because there wasn't enough disc left to biopsy.  The past 6 weeks have been amazing!  I can't get over how good I've felt.  I thought we had finally after a 3 year battle fixed things for the time being.  Last week...the pain came back...not as strong...but it's still there.  I have no idea what to do now.  My question is this...are there any diseases that attack the discs of a person's spine?  I know that the discs do not have a blood flow supply so once they begin to fall apart...it will continue to degenerate.  I used to be this active 20 year old...and now I feel like I'm 60 and well on my way to becoming a pain medicine addict if something doesn't change soon.  I've done a lot of research but I can't seem to figure out what this is.  It's driving me insane...if anyone has any suggestions or advice as to why my body is continuing to expire these discs PLEASE write me back! Even if your suggestion is way out there...I will do what it takes to if nothing else cross it off my list.