there seems to be no reliable resource for minors. all of them involve notifying your parents in some way or are there just to prevent you from killing yourself. there are no resources i could find, online or in person, free or paid, that provide private care.
As an adult who has raised children and worked in doctors’ offices, yes, this is a good idea. If there is any way for you to get help in your state without your parents knowing about it, your doctor will know the steps. If your parents usually stay in the exam room with you, ask the office to make sure you get alone time with the doctor during your visit. You don’t have to tell them why. They will help you.