I think Elysium has a good idea. Talk to your pediatrician and be honest and please mention that you have already cut yourself and that you desperately need some help.

It is sad that your friends aren't supportive but not surprising to me as I was always picked on and even had my so called friends play mean tricks on me.

It may be that your dad doesn't listen because he either doesn't understand what you are saying or he doesn't know what to say to you. Sometimes parents are like that. Try to keep communication going with him and perhaps say, dad, I need to have a serious discussion with you. When can we talk about it?

Keep trying. Don't give up. You do need help and that is nothing to be ashamed of. Please let us know what you have tried to do to seek help and how that goes. We will keep supporting you and help you to find some help.