mental illness

I've been struggling a while mentally and I've recently reached out to a counselor and parent because my mom thinks it's a bodily thing like thyroid and my boyfriend thinks it's all in my head. I met with a psychologist Monday and he says he's pretty sure I have clinical depression. I was scared to tell my family and my boyfriend as they do not believe me. It was no surprise to me that when I told them they thought I was making it up or making it bigger than it seems. It really is taking a toll on me and my school work. In past years I have self harmed and hated myself in so many ways and I've tried to change and be better and make it stop but I just can't. I don't know what to do anymore.