I have nothing to live for.?

You're closing yourself... study if you're too young to get a job, otherwise get a career and help your mom if you can, start with a part-time job. Killing yourself is not the solution, this will bury your mom - Is that what you want? Focus in what you have to focus... put goals in your future and you'll reach them, put all of this energy into it and you'll remember this message then.