Try visiting any physiotherapist near u.. they will perform some simple tests manually... U most likely will have weak back and core muscles along with hamstring tightness.
Next Steps
they will guide u with some stretches and strengthening exercises for low back and abdominals.
Health Tips
do not do exercises when in pain... strictly... till then take some heating pad or hot bottle and apply any ointment... remember no massage till u rule out the problem.