This is very normal, Macbeth often has these outbursts.
Finally I am King!
Macbeth and his wife, lenox and Ross all attend a banquet. Banquos ghost appears to Macbeth. Macbeth becomes very agiatated as Lady Macbeth tries to hide the truth. Macduff did not attend as he is looking for help, he is also very suspicious of Macbeth.
Macbeth goes to see the witches again. The witches lead Macbeth into a false sense of security, as he believe he cannot be killed by anyone. Macbeth then sends murderers to kill Macduff and his family in England. Macduff begs King Duncan's son, Malcolm, to go back to Scotland and become King. Malcolm then goes into war against Macbeth.
Lady Macbeth goes crazy with guilt, but no doctors can help her and she commits suicide. Scotish Lords agree to help Macduff and Malcolm overcome Macbeth. Macbeth still truly believes he cannot be killed by man. Macduff was born unaturally by a caesaren section, which he tells Macbeth. Macduff kills Macduff kills Macbeth and Malcolm becomes King of Scotland.