If you are Under 16 and worried about seeing a doctor or nurse anything you say to one of the doctors or nurses will stay between you and them. They won't even tell your parents or any other family member. The only reason they will consider telling someone is to protect you and give you the right treatment.
But they will ALWAYS talk to you first. Confidentiality applies to everyone, even under16's.
The doctor or nurse will only ask you personal questions to help you; not judge you! The doctor or nurse has probably seen someone in a more difficult situation, so don't be embarrassed when talking to them. Always remember they are there to help you!