The criteria for diagnosis is that the symptoms are invasive in two different environments. Usually, for kids, that’s home and school. If there’s absolutely no problem at school, then you may continue to run into this issue.
However, as Rob said, doing well in school is a LOT more than grades. Behavior, social experience, and emotional sensitivity and issues are an important aspect as well.
Whether it’s ADHD or not, in the end, you need help. You shouldn’t have to live the way you are right now. You may need a second opinion with a psychiatrist or with the evaluation and diagnosis. Make sure you find someone who is very experienced in pediatric ADHD. Follow your gut, and keep working at it.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism