You can make a private appointment with your regular doctor. They can rx meds if needed, or refer you to psych services if they feel its needed. They would not call you an ambulance unless you are having some sort of immediately dangerous crisis.
You can also look up crisis or community mental health phone numbers for your area. They do not have to tell your parents, but if you are underage, they will have to know at some point. You can ask for assistance in educating/informing them. If you are an adult and your own guardian, they do not need to be informed unless you say so.
Good luck to you.