Getting Back Pain. Suggest Some Best Medicine
The description of your pain is not detailed enough to suggest a direct diagnosis.
Was there any precipitating factor? - Like lifting a heavy weight / unusual posture or exercise?
Is this the first time? Or, you have had it before?
Do you have any other problem - now or before?
I presume a 'no' for all these - in view of the short duration and young age.
The pain will improve with NSAID (ibuprofen, diclofenac, celecoxib and so on. Sometimes they can cause stomach irritation in some people - Take them after food. Simple Paracetamol alone and or in combination could also help.
At times, a muscle relaxant - like chlorzoxazone or methocarbamol - is added.
You can get a proper prescription from your General Physician.
Good posture at work and home are important in the long term. Yoga can help.
Go for massage, fomentation and physiotherapy - if severe.
Good luck