It seem that you have a first attack of low back pain
, that has occurred due to long sitting or bad posture. This pain in self limiting at starting stage but you have to be careful in future so that you wont get this type of pain again. Certain precautions you have follow are:
1. Alternate hot and cold
2. Use hard bed to sleep, avoid pillow.
3. Change your posture while working on computer every half hourly.
4. Do regular exercise by consulting you physiotherapist.
5. Avoid jerky movements of back.
Hope this will help you.