Please avoid bending to the front, don't lift anything heavy. Hot packs will help to relief from pain. (Twice a day) . Stretching of back muscles.

Hot fermentation and stretching exercise of spine. Posture corrections must

https://www.youtube.com/watch?v=HxvRQ9ZJ8vQ Chiropractic Mobilization will help. Avoid bending in front. Postural Correction- Sit Tall, Walk Tall. Extension Exercises x 15 times x twice daily. Apply Hot Fomentation twice daily

Tour S.i joint needs to be glided ...consult a manual therapist

Do hot WATER fermentation twice a day for 3 days. If there is no improvement in 3 days then you need you take inferential therapy for a week. Dont do heavu exercises, only active movements are recommended.

You can start taking hot formentation for now 10-15 mins thrice a day . Also you can start maintaining correct posture while studying n working that will also help you to some extent . And visit a physiotherapist and let he/ she guide you with proper exercises for strengthening of your back ( upper/ lower) . And make sure you do atlst concise set of exercises daily for 10-15 mins

The treatment depends on where your pain is, upper or lower back. You would be better off visiting a physiotherapist  as they would assess the structures; ribs, spine, tight muscles, any referred pain etc... The easiest thing, exercisewise is to walk and make sure that you swing the arms when doing so.

Hot formantation 15min twice a day Do the Spinal extension exercise Spinal isometric exercise