Hello, thanks for the query.
Previously you were a patient of heart burn and acid reflux
Extra work leads anxiety
and that too in the age of just 17 yrs, anxiety produces acid reflux and gastritis
( Hyper acidity).
Above mentioned two things causes sour mouth and burn in stomach.
prolonged gastritis is a bad thing and either you have to reduce anxiety or work load.
Extra fried food with high amount of spices , worry , tension, stress( work) , these all are predisposing factors of acidity, so , if possible avoid these and you will feel relaxed.
Good luck. Dr. HET.