No period severe lower back pain loss of feeling in legs inability to walk or sit up violent muscle spasms pelvic pain frequent urination always cold?

See your physician! Some of your symptoms are very concerning, but with just a list of symptoms it's not possible to know if they are all related. Nor is it helpful to speculate on the possible causes as you need to see a physician to discuss these symptoms in detail, explain your medical history and have he or she examen you. Only then will you arrive at a diagnosis. Don't waste time trying to self diagnose>See Dr.
Be seen . Clearly if you have lost the sensation in your legs and you can not stand or walk you need to be seen urgently, even if it means going to the emergency room.