It's look you recently coming in this lifestyle ,first you need to check your hip resting possition which is base of your posture ,and bad posture means bad spine position so take a assessment on posture , get aware of your shorter muscle and weaker muscle , which joint movement restricted etc.
Start rehab program
Next Steps
hot pack + stretch ( total flexion postion)+ back & core strength ex.
Health Tips
this pain is good ,trying to tell you that something is wrong with your posture so adjust himself for forever.