Greetings, sorry about the pain. Not to worry, it is just kind of stiffness at muscle level due to poor usage.
Next Steps
get to see a physio and get trigger point therapy, massage done. next as you start to feel better your physio will teach you exercise so that you return to normal self. all these will take atleast 2 months if not more to show 100% results.
Health Tips
if any questions do let me know.