Hello mam...well you yourself have the answer to your back problem....( its right)-inappropriate postures while commuting and long working deskjob work requirements.... many IT/management people have these problems as young as 20 years... but what is it that you need to do to overcome this... well yes a fit and healthy lifestyle is important...Eat right and exercise right . You need to develop strength in your lower and upper back muscles...static exercises for back and swiiming is a great way to develop tensile strength in these group of muscles.. for the time being you can apply any diclofinac based gel 3ice a day to the affected area and wear Lumbosacral belt of your size while commuting(it can be worn from inside).if you have a bit of discomfort you can walk into any physiotherapy OPD and ask for TENS/IFT and SWD sessions ....5 days of these sessions should make your pain dissapear....also you can do hot water formentation at home. Since you know the reason for your back ache hence it is not advisible to take painkillers or go in for any x-rays at this point of time. Do resort back to me regarding any furthur querries. Take care. Regards

All the postures u explained give stress to paraspinal muscles that can give back pain. 23 is very young to get this type of pain learn paraspinal exercises from ur physiotherapist also get assessment done for any pathological pain too. Visit wwwdrrajivmehtacom for more details