Thanks for using healthcare magic.
I have gone through your history.
You might have performance anxiety due to stress related to exam.
Lexpro is escitalopram which is very good anti depressant
Valdoxan contains agomelatine which is novel, good anti depressant drugs. But you must consult your psychiatrist
before starting valodxan on your own.
You may also get benefit by propranolol
for performance anxiety if any. You may have prescription for it from your psychiatrist.
You may also benefit by doing yoga, meditation or breathing exercise