Suicidal tendencies in Paradise?

There was no Death in Eden before the Fall, right?

So how could Adam and Eve have known what 'death' or 'dying' were supposed to mean and that this was something bad?

Did God explain this to them in a private session that's not recorded in the Bible? And if he has explained the concept to them then why would their first reactions afterwards be to want to commit suicide? Did they realize that they were prisoners in a golden cage, alive but unaware and unconscious? Did they realize that they had to break out of the nest in order to grow up and be able to think for themselves?

Usually people commit suicide because they have lost hope and/or because they want to escape their own private Hell.

So what exactly did God tell them?

Did Jesus HAVE to die?

OR could his mission here on Earth have ended differently?