I think Cmpgirl explained all very well; I agree with all she said.
I want to add how proud I am of you that you lost so much weight. I can imagine how much hard work you put into this.
DDD is a condition we all leave with since age 25; our joints, spine starts to change at age 25, for some even earlier. DDD, Stenosis,Atrthirities - conditions which come with territory.
With aging those conditions usually progress, especially in non-active people. Excercising, active way of life, yoga - all helps to put progress of DDD on hold. Loosing weight is step #1 to change your life to better and to become more active.
Just make sure, please, you get enough nutrution for your bones, for your body. Good supplements (not the cheap ones though which may do more harm than helping you) can contribute to your healthy life style...
Best of luck to you and keep up with a good job!