I know it sounds lame but try using the Law of attraction to improve your llife.
I also read about on a website called near-death.com that someone did commit suicide and she did end up in a dark place but God rescued her. I think that what happens to people who commit suicide goes on a case by case basis. I think God gives people what they need in order to come back and live a good life.
At the moment I wouldnt recommend it but Im no expert!!