Once Macbeth assaults the natural order in Scotland by murdering the king, he is crowned king because both of Duncan's sons flee Scotland.
Once on the throne, Macbeth has very little time to enjoy his reign as king. He experiences one high point as king, the dinner he has with his family and friends. Even this evening of celebration is disrupted by the haunting presence of Banquo's ghost. An apparition that only Macbeth can see which causes him to appear insane, losing his mind and under the influence of some crazy spell.
This is the beginning of the end of Macbeth's sanity. His mental health begins to deteriorate after he sees Banquo's ghost. He becomes more and more paranoid with each passing day, feeling the need to eliminate all threats as he sees them. His method of dealing with his perceived enemies is to send killers to murder them.
Macbeth becomes obsessed with the idea of knowing more about the future, visiting the witches for the second time, he leaves them with a new sense of purpose, to kill Macduff.
Macbeth's mental instability is shared by Lady Macbeth who goes mad with guilt and grief, particularly after the deaths of Macduff's wife and children. Macbeth loses the affection and companionship of his wife, his partner and cheerleader in crime, commits suicide by throwing herself out the window.
Macbeth literally sacrifices everything that makes human life enjoyable, sleep, food, friends and the love of his wife. He is miserable by the end of the play, I think, by the time he is confronted by Macduff, and realizes that the prophecies have not protected him, that he is ready to die.
Macbeth sacrifices his integrity, his self-respect, his sanity and his soul in exchange for power and a chance to be king.