I would have to say hell, but I think it would be possible to still go to heaven, let me explain. I believe that you can lose your salvation, if you fall away from God. So if you kill yourself you have just commited murder, and therefor sinned and seperated yourself. When I was in a depression I thought about it a lot. But the thing is I'm sure if you kill yourself, but are still alive, than you will go to heaven. For instance, when your jugular is cut, you have 30 some seconds until you dies of blood loss. SO if you truly mean your repentance than you will go to heaven.