I agree with the poster above me that you should confide in your parents you feel the need to see a doctor, as you are having some issues that are causing you concern. You don't need to go into great detail; just tell them you are not feeling well and want to get checked out. Your doctor will be able to assess you and reassure you once you are in their care.
Try to stay calm and focused. It is easy to get upset and panic, but try to relax knowing that taking the right steps for yourself will lead you to a good outcome. Good luck, girl!