How you address the fears is a whole different kettle of fish...so to speak.
I went on and got second and third opinions from regional docs while I could still 'get there'? And also before IT'd done too much damage, as my initial neuro disregarded all my concerns almost from the 'get go'. I've had this all since '2003' and I truly wish it'd go away! {I've CIDP, btw. Tho the neuro writes down new 'takes' on the diagnosis -all requiring the same treatments, but - still keeps me on-guard?}
That 'pop' in the back is truly something that should be COMPLETELY explored? Honestly? It could be one, or the other, or both! Nothing is exclusive with the human body!.... Spinal MRI's w/and w/o contrast should be done, as well as both complete blood panels and metabolic panels. AND BE SURE TO ASK FOR COPIES! I go directly to the lab to get the blood work done and there I ask for copies so's the lab doesn't have to send them to my dozen plus docs...I get and make copies of the test results and pay attention to the '*' asterisks and the near asterisks - the hi's and lows... Beware of Vitamin B-6? Please. That's a supplement that's often tossed into other ones and it can add up...{I'd thot I was supplementing myself well, until I really looked closely at the labels-found I was getting 6 times the normal requirement for B-6 ....which can cause neuropathies itself? Switched to a pre-natal multi-vite which has lots of what I want and need, and added on to that as needed. Mrs D is one special and valuable resource to ask questions of? But remember, that she can't prescribe you any particular course of things to take? She reccommends and with solid back up! The choices of what you take, how and when are yours tho..
I too have 'no thyroid' and it was one mess getting to know about that! Do read CAREFULLY The prescribing directions about taking synthroid and calcium supplements...,it can get complicated? IF you're chugging all your AM pills in the AM? Including the Synthroid and Calcium? You gotta read about this? It's a no-no and makes taking lots of other stuff more complex.
I too have osteo [BIG time] And I've found that even knowledge too late can help? But the knowing SOONER is far far better! 's and hope - j

PS HANG IN THERE! You are NOT the only ONE! Keep faith in yourself and fight for ALL the right diagnoses! I say this as I've gotten more diagnoses than I can spit on since my 'onset'. I truly didn't do anything to 'get' them? Just the luck of the draw and an immune system that went 'TILT' I believe you get my drift... Keep FAITH! Ask questions, no matter how silly, sometimes, those are the key's to it all!