I agree with SeptemberMorn on the idea of telling a psychologist first before your parents... but if you need their financial support or approval to do that, then I would suggest you talk with a school counselor or such first. AND I wouldn't reveal the cutting issue at the beginning. The Overreaction would most likely be overwhelming.

You might also imagine all the things your parents would say... because of the family dynamics... this way nothing they say will "throw" you. DO consider what you WANT to hear from them when they hear.. and how they might say it so you recognize it, too.

Please research anything I suggest before believing...