Is Macbeth as confident as he claims to be in Act 5, Scene 3, of Macbeth?
No, he seems to be losing confidence steadily but trying his best to encourage himself as well as to present a confident manner to his dwindling number of followers. At one point he says, "Seymour--I am sick at heart / When i behold -- Seyton, I say!" (5.3.23-4). He is probably intending to say something like, "I am sick at heart when I behold everyone deserting me while the English forces keep advancinig." The fact that he has to shout for Seyton three times before his attendant shows that he is losing the respect and loyalty of even his servants. Then he says, "I have lived long enough" (5.3.26). At this point he is clinging to his last remaining hope, which is that that prophecy of the witches will somehow prove correct: "I will not be afraid of death and bane / Till Birnam Forest come to Dunsinane." Later he tells Macduff: "I bear a charmed life, which must not yield / To one of woman born" (5.8.15-16). Shakespeare seems to be trying to portray Macbeth, not as an out-and-out villain like Iago and Richard III, but as an essentially good man who is misled.