What Could Extreme Shivering Followed By Muscle Cramps And Pain In Upper Back Indicate?

Trying to determine cause of my issue... last night I suddenly had uncontrollable shivering and I was very cold. After putting on some extra layers I went to bed to try to get warm but could not find a comfortable position as all of my muscles were cramping which caused me to have shallow breathing. I literally could not stay in one position for more than a minute due to muscle cramping. After a couple of hours I finally warmed up but was extremely weak and continued to have issues with muscle cramping and being able to find a comfortable resting position. I was finally able to go to sleep and slept for 5 or 6 hours. This morning, i woke up feeling extreme muscle soreness all over... like I d been in a losing boxing match... but in my chest (lungs) and buttocks in particular. I also have a cough that is only slightly productive and hurts my lungs when I cough. I did have some occurrence of sore throat and congestion over the past week and also earlier in the day yesterday had a sharp pain in my upper right back area that continued throughout the day. I took some Naproxen this morning and that is helping the muscle soreness to some extent but I m just curious what might have brought this on as I ve never experienced anything exactly like this before.