i've got mixed feelings on your post. that is, if you're 18 this is a total invasion of your privacy. not cool. however if you are 18 and your parents are totally worrying about you and your behaviors, plus you wouldn't open up to them, they may have felt you gave them no choice. i'm not defending them...i'm not in their shoes, but clearly they love you a lot and are very concerned for your well being...cutting, dope, saying you're fine when they knew you weren't fine, etc. some of the issues you have discussed in this forum indicate you do need professional help, IMHO. i'm sorry you weren't able to meet them half way so it didn't come to this desperate measure on their part and a violation of your privacy on your part.
if you are under 18 they do have the right to invade your privacy if they feel your health and well bring is in danger.
i hope things will work out for you. i realize this is a break of trust. i hope you and your family can get to the bottom of what help you need and be supportive to you.
and if ranting helps, i'll listen. it helps sometimes to just let it all out.