Education does provide knowledge but it may not be synonymous with wisdom. Similarly, high marks and a very good academic career do not reflect what an individual is/has become/becoming otherwise.
Personality is multidimensional and should be allowed to develop adequately with participation in various activities. For a successful individual the mantra in today's world is no more of just education and marks but also other components and skills - namely assertiveness, social skills, co- curricular activities, communication skills, emotional intelligence etc.
Usually teenagers come under the pressure of doing a particular course because of feeling pressured, because they feel they will hurt others if they opt for anything else. This leads to pent up frustration, and results in emotional problems which can be very devastating because it would then seem that studies has led to this.
I would advise spending time having a chat with your daughter, try understanding her as a person as an individual rather than seeing her from the lenses of studies - marks - courses - gold medals, etc.
Thereafter it would be important to take her to a clinical psychologist, because it is better resolved early than later when emotional upswings may require use of medications.
Be patient - spend time with her and do not be guilty of anything.