Stefan, you need to follow people's advice here. There is help out there but you have to take the first step and reach out for it. You are 16, that's a difficult age for most people, it makes it harder for you to deal with grief. That doesn't mean your suffering is necessary. You are punishing yourself by not getting help with this and there is no need for that. When you are depressed, you think you'll always feel that way and only death can change that. I know because I've felt like that too in the past, but guess what: I don't feel like that anymore now and I'm still alive. That's because those kind of desperate thoughts are the depression talking, they may feel completely true, but they're not. There is another way.
So please Stefan, pick up the phone today and call your doctor, or make an appointment with your school psychologist. These people will not judge you and what you tell them is confidential. They are there to help you.
yes please ... someone will listen i promise ... nobody wants another person to be depressed and sad and lonely! they will help you pick yourself up, doctor, school counselor, someone like this! sounds like it's getting worse for you, these things don't get better on their own:(