Teenager - school/home experiences very different

[feedbacker]

I have name changed for this thread
Our teenager has been showing signs of stress and anxiety at school which have resulted in talks about self harm. These are not visible ever at home at all. New to school this academic year and never any similar situation before. Seems to have escalated in the schools view very quickly over the last few weeks and not evident at all in prior years or at prior school - we have appointments to try and find the help needed- looking to understand if anyone else has been in this situation and any advice - very strong academically - no changes in grades, eats well, sleeps well, competes in sport to very high level and no changes in these habits - we do not believe bullying is involved but do believe that harming are discussed at school (which i suspect may not be uncommon)