Hello dear ,
Im here to help you in understanding ur condition
In general gastritis can be caused due to acid reflux from stomach (below) to oesophagus i.e food pipe (above) which can irritate your throat and make you feel like there is something stuck in your throat.
Next Steps
As per your height and weight and you being student ,im in opinion that you are not having proper food timings,improper diet and sleep irregularities,stress and other foods may be triggering your cause.
Health Tips
Try to Have proper timely meals everyday,