Write a diary entry (from Macbeth's perspective) about how Macbeth feels in act 1, scene 7.

Act 1, scene 7 deals with Macbeth and Lady Macbeth arguing about whether they should proceed with the murder of King Duncan. While I will not write the diary entry, here are several ideas you should touch on:
Macbeth feels an overwhelming guilt because he is Duncan's host and should "not bear the knife itself." In addition, Macbeth praises Duncan's goodness as a person who has "been / So clear in his great office, that his virtues / Will plead like angels." Your diary entry should include Macbeth exploring this guilt.
You must also touch on Lady Macbeth challenging her husband's manhood. She tells him that if he commits the murder he would be "so much more the man." In addition, she says that if she had the opportunity, she would have "dash'd the brains out" of a baby suckling at her breast. Without exploring Macbeth's shame, your entry would be incomplete. Ultimately, it is this shame that drives him to commit the murder. 
This is somewhat related to the second point, but Lady Macbeth is the one who devises the plan to kill Duncan and place the blame on the king's chambermaids. In this hypermasculine world, Macbeth allows his wife to control the action. You must touch on this swapping of gender roles. 
While you must touch on the above points, your entire diary entry must focus on the conflict Macbeth feels because of his wife. 
Tonally, your diary entry must be one filled with angst. Macbeth is confused and is feeling somewhat bullied by his wife. He must feel trapped knowing that he has two choices: commit regicide or betray his wife's belief in him. You have to remember that Macbeth, up to this point in his life, has been a good man and a loyal servant of the king. The action he is taking will betray everything he has worked for in his life to this point.