Hi Madoreck!
I guess that I know pretty well how you're feeling. I'm a high school student as well, graduating this spring but so insecure about my future. Before I knew what I want. Graduating is a fine thing and I should be happy and relieved, but I can't help my anxiety when I'm not seeing any future for me. Those suicidal thoughts are familiar here as well.
I'm so sorry for your situation. And sorry that I don't know what to say to help you! If I still could do something for you, feel free to tell me!
All the best!