Are Suicides Automatically Doomed to Hell? What of Judas?

Are suicides automatically doomed to Hell? I've heard that, but I read something in the New Testament Book of Matthew that makes me think that, maybe, Judas was not. And if he was not, then maybe there is hope for others as well.

We have to start with the thought that Jesus was who he said he was; the son of God, God on Earth, both divine being and human. If you grant that, as all Christians do, in some degree or another, then we can move on. If you don't, then the rest of this will likely have no meaning for you. He often spoke of what was to come; in the near future, in the far future, in the end times. His disciples asked him things and he would answer, sometimes in parable and sometimes straight out.

In Matthew, Chapter 19, Jesus had been telling a young man the things he should do in order to have eternal life. Afterward, Peter asked Jesus what was to become of the disciples. Jesus told him that when he sat upon his throne, there would also be another twelve thrones and that the disciples would sit on those thrones and be judges over the twelve tribes of Israel. In Chapter 27, we see that Judas hanged himself out of remorse, for having betrayed Jesus.

At the time that Jesus said this to Peter, Judas was still alive and one of the twelve. Did Jesus make a mistake? Did he change his mind? Did he just lie to Peter, so as not to give away the secret? I can't imagine that he did any of those things. If Jesus is God, and therefore knows all things, then he knew even then that Judas would betray him when the time came for it to happen. He also had to know that Judas would hang himself. Yet he didn't say that there would be eleven thrones, or that eleven disciples would be joined by the replacement for one who would disqualify himself.