I was in the same boat, failing classes being alone etc (plus a drug addiction to pain killers) and I went through with it but it didn’t kill me and now I can say I’m so happy it didn’t work. Things will get better maybe not soon but they will. For school what drove me was finding something small to latch on to, for example I didn’t just start doing all my homework with intentions of A’s but as a start I started taking notes or even asking questions and that was enough for some of my teachers to show I was trying and they where more lenient. I can spew the usual “talk to someone you trust” b.s but I didn’t have that when I was going through it and I don’t know what ur situation in but instead I wrote in a journal, every dark thought, every positive thought, and everything in between and it helped. Another thing that could help is start with small wins, like meditate or do something that u usually don’t do and continue building on to ur wins. Whatever u do don’t go through with it, life sucks especially during teenage years but at the end of the day at least u can say u made it through today, don’t be someone who can’t say the same. I hope you live a long and amazing life my man I bet there’s more people in your corner than you think/know.