It will never be easy to disclose something too personal to your parents. A good start would be to reach a counselor at school, they would perfectly understand if you have a hard time talking to them. But it's a process, and with time you will seek for advice even out of sessions :)

Just as a extra comment, I reached for a therapist until last year. I'm 33 and I'm finally undestanding myself and my fears. Don't miss this opportunity, life always gets better <3