Hi
Welcome to the MedHelp forum!
It is unlikely to be MS. It can be fever, rheumatoid arthritis, stress, high BP, etc. Get your BP checked. Take something for pain. If it does not help, go to a walk in clinic. Take care!
It sounds like tension to me,because you are stressed about this you are tensing your whole body up causing your muscles to become sore and stiff,and the headaches are a perfect example of this, i know you are worried but please try to relax,i am sure this will ease your symptoms.