I need help my mother is so unempathetic

I already know what I'm going to do. I'm absolutely done. I don't need anyone either telling me their story or telling me to stay. I just want advice on what to do in this particular situation. I am so extremely depressed I have barely left the house all week, I don't shower anymore I don't do anything with my time. I'm just done. I didnt go to school yesterday and my mother just called me ridiculous saying "this won't go in college/uni etc" as though I'm planning on living to that age. It's not like she's unaware. I have very bad anger issues. I've screamed in her face that I want to die and that I want to kill myself. Recently. She's done nothing. Only told me the next day how horrible my behaviour is and now that I'm not going to school today she said she's calling my work to tell them I'm not allowed to work there. I'm 16 by the way I'm not some adult baby. That job is the only freedom I have right now. I suppose it doesn't matter much seeing as I'm going to off myself. It just makes my last days here horrendous and unbearable. The one person that I thought would understand in my most difficult moments is just cold and refuses to understand. She keeps saying my behaviour is horrible but she can't begin to comprehend why the fuck I would be acting like that. I've tried endless times telling her. It doesn't get clearer than "I want to fucking kill myself". Apparently that's difficult to understand.

edit: these aren't the only reasons I don't want to live, I could write a book detailing everything but there's just no point in that.