How do Macbeth's last 2 speeches in Act III, scene 4 reveal the deterioration of his character?

This entire act shows Macbeth is deteriorating. First, he is unable to entertain his guests because the ghost of Banquo haunts him from Macbeth's seat at the table. The fact that this display is public is in sharp contrast to the night Macbeth murdered Duncan. In Act II, sc i, just before the murder of the king, Macbeth also hallucinated, that time in the form of a dagger. However, at the beginning he was able to maintain his public persona and act the part of the innocent host when the murder of the king is discovered in the morning. In the third Act, Macbeth puts his emotions and guilt on display in front of all his lords, yelling at the ghost no one else sees. In addition, Macbeth shows his paranoia and guilt are both getting the better of him. He explains to his wife that his has spies posted in every house to monitor the lords. He seems to feel as if he has reached a point of no return and cannot stop killing. He says, "I am in blood steeped in so for that, should I wade no more, returning were as tedious as go o'er." In addition to that, he has lost faith in his own judgment and feels he must now depend on the witches (whose obscure visions helped to begin his bloody quest for the throne) to help him decide what to do next. He plans to see them in order to know what the future holds for him.