Advice to parents of teens who self harm

Last year our teen mentioned she has friends who self harm and has mental health issues. This year, our teen is also one. We are shocked, saddened and a lot of other emotions when we accidentally found out, using a ruler or ballpoint to inflict. She does this whenever she gets scolded and punished/grounded… which becomes more frequent lately with the sudden change in her attitude and outlook in life. As far as we’re aware, we have provided her everything she needs so we really don’t know where we could have gone wrong. The scolding is to instill discipline and correct the wrongdoings. Any reasonable pyschiatrist to recommend? Can the form teacher or school counsellor help or speak to us? We know she’s running for leadership role so we’re worried if speaking to them could harm her chances to become a school leader…