Oh, Gosh! I am so sorry to hear about your loss. I know the death of a student or former student always effects the class dynamic. Last year at graduation, we had six roses on the seats of seniors who should have been getting their diplomas but had been buried the month before as a result of a horrible car accident on prom night.
My students also always comment on the depressing themes of literature we teach in class...especially with Shakespeare's Romeo and Juliet, Macbeth, and Hamlet. As a result, I try to introduce some of the comedies and also to focus on the comic relief of the tragedies themselves. Tragedy is part of life. It is the ying and yang...the balance that we must all strive to achieve.
In class, I try to balance our discussions with real-life lessons and apply what we are reading to as many real-life sitatuations as possible. I hate to think we are contributing to the problem of teen suicide or even an obsession with death, but those who are bent on it will probably find a way regardless of the literature we read in class. As teachers, we just need to be as vigilant as possible and refer the students we are concerned about to their counselors for more in-depth probing and the help they need to get back in balance.
While there is humor to be found in all literature, there is nothing humorous about the death of a young person ...especially one who lived and sat in your class. Again, I am so sorry for your loss.