Thanks for asking me to respond.
The most common reason for back pain at your age is usually disc related. I would suggest you to avoid bending forwards and not carry heavy weights for the moment.
Apply a hot water bag to the back and keep a pillow under your knees while lying down in bed. Give yourself adequate rest.
You may need pain meds, specifically anti inflammatory meds, and muscle relaxants of the pain is severe. I cannot prescribe meds as Practo prohibits me from doing so.
Once pain reduces you need to core body strengthening exercises, and a good physio can help you with this.
Please visit our pain clinic for non surgical allopathic treatment.
There may be many reasons for back pain, ours very difficult to advise you anything without examining you.
There is good chance of treating it, but I have to examine first