None of Charlie's friends are really talking to him after the mess he made during the truth-or-dare game.
When Charlie goes to visit his aunt Helen's grave to clear his mind, it doesn't help.
He worries that he's brought everything on himself, because his psychiatrist says he's passive aggressive.
Near the end of the letter, Charlie has a wish: "I just wish that God or my parents or Sam or my sister or someone would just tell me what's wrong with me. Just tell me how to be different in a way that makes sense. To make this all go away. And disappear" (3.12.14).
He concludes the letter by telling us he bought some pot from Bob and has been smoking it almost non-stop since. That's called a not-so-genius coping strategy.