Thanks for query,
It seems that it may be due to your posture as you are working long on your computer.
Have proper posture while working on computer,
Take a round around off an on while working.
You might have lack of exercis,go for daily exercise like running,swimming.
As you are mother of 3 children you might have some calcium deficiency
Take more milk,nourishing diet and multivitamin
Do some spinal exercise.
ok and bye.