Your problem is related to Posture issue(Mechanical).
You need Proper physiotherapy related to stiffness,muscle spasm & lack of flexibility. Electrotherapy useful for time being.
Manual therapy is really very helpful like Maitland.
Flexibility & Strengthening exercises are very important.
You will be fine definitely.
Next Steps
Take Hot fomentation over affected area twice in a day with Dynapar gel for 15min.
Use Backrest during working on seat.
Move/Walk/Self stretch in different ways in between in every 2hrs during working.
Go for Blood test- Vit.D3(12hrs Fasting)
Health Tips
Avoid sleeping on Hard surface as well as slouching posture.