hi and welcome to PC.........i am so sorry that you are having trouble right now. you've come to a good place to get support and find people to listen and talk to you. i need a bit more info and am going to ask you "20" questions.
how old are you? do you live at home with your family? is there anyone in your family that you feel close enough to confide in? an aunt or someone a bit removed from your family's home?
if you don't have anyone else and you are younger, you may have to speak to your parents. if you feel that you need help, i believe they will understand. depression is just like kidney disease or cancer. it's an illness and i am sure that your parents would want to find help for you. i definitely would want you to seek help if you are upset enough to cut......
if you are in school, are there counselors there? or a trusted teacher? someone IRL that knows your family and might help you talk to them?
i don't know if i've been very much help, but please keep me updated. you will find a lot of support here......xoxox pat