Back pain and tiredness all the time.

I am Aditya Wadkar, 28 years old from Thane. I experienced a sudden and sharp pain in my back when I jumped 2 months ago. (I dont know if this started 2 months ago or before that because in my daily schedule I never come across a situation where I have to jump or skip ever). But now from past 20 days I have started feeling stressed out and tired for no reason (I do all the work on my laptop that means almost whole day I have a sitting job. My job is not at all stressfull.). My middle back and lower back is always stressed. It feels like I drove a car for 8 hours with the most uncomfortable seat. Now a days that feeling is continuously there all the time for no reason. I have started to walk and jogg 5 -6 kms daily in the morning as I am 5ft 6in and my weight is 88kgs. I have tried changing my chair my sitting postures everything but nothing helps. I am scared if this is a beginning of something serious. Please help me.