In Oedipus Rex, how does Oedipus learn his fate?

You have asked more than one question so I have edited it
down to just one question. It is at the end of Scene 4 when Oedipus finally uncovers the
truth that has been hinted at for so long. Oedipus finds a Shepherd who was born into
slavery and served the old king Laius for all his life (the father of Oedipus). The
Messenger who is present during this scene reminds the Shepherd that he gave him a baby
boy to bring up as his own. The Messenger states that it was Oedipus who was that boy.
The Shepherd tries to evade further questioning and confirmation to the best of his
ability, but at last he is forced to admit that he was given a child from the house of
Laius:

If you
must be told, then...

They said it was Laius'
child;

But it is your wife who can tell you about
that.

It is the Shepherd who
reveals to Oedipus the prophecies that had been given concerning him, that he would kill
his own father. Ironically, the Shepherd explains that he pitied the baby and therefore
gave him to the messenger to have a new life, never thinking that by so doing he would
actually damn him. Note how Oedipus responds at this critical moment of self
knowledge:

Ah
God!

It was true!

All the
prophecies!

-Now,

O Light,
may I look on you for the last time!

I,
Oedipus,

Oedipus, damned in his birth, in his marriage
damned,

Damned in the blood he shed with his own
hand!

It is then that Oedipus
exits the stage to blind himself, to symbolically prevent the sight of the knowledge
that he has just discovered.