Sir, based on your history I suggest you to do yoga, daily jogging and meditation on regular basis since most of the time it can be psychological due to the level of stress you are going through in your work life. Try to do alternate leg raising exercise atleast twice daily, here you have to lie flat on a floor and raise your leg as high as possible keeping it straight, without any support while keeping the other leg flat on the floor, maintain this position for atleast 10-15secs and repeat the same with the other leg. Do this for atleast 5 sets daily twice. Try to develop sleeping on the floor on a matt without the bed, this things will help have to develop muscle strength.use hot fomentation whenever you feel pain, avoid depending on pain killer. Since you have mentioned that you do desk job, generally poor sitting posture can also be a cause, nowadays there are chairs available for good spinal support,you can use that.all this things takes atleast few months to build your muscle strength so if you are not satisfied try to consult a orhopedician and a physiotherapist.