This is mainly due to the fact that u have
Chronic bad posture
U dont give your body time for exercises
Your muscles are in a state of atrophy.
This all is due to the fact that you give first priority to your work and not your health. Please consult your orthopaedic doctor for appointment as this can be something more than a muscle spasm. Likely possibility that this could be due to a prolapsed disc.
Please get your investigation after consultation.
Health Tips
In the long run, u need to exercise for life to prevent this happening again.