I have great sympathy for Hamlet because in all of his interactions with those around him, he feels a lack of trust. With the exception of Horatio, there is no one! His mother quickly remarried; his Uncle is a murderer; his girlfriend may love him, but is allowing her father to use her to find out more about what Hamlet's state of mind is; his friends Rosencrantz and Guildenstern as primarily loyal to the king and queen, not their friendship with Hamlet; Laertes may have been a friend, but Hamlet's killing his father understandably makes Laertes a threat. Hamlet's entire character is shaped by his reactions to those around him. Nearly every scene in the play highlights this. Your essay could talk about how one character in particular affects your response to Hamlet, or how two or three different characters affect your understanding in different aspects of his character. There is so much you can do with this topic!