I too am very sorry about your friend and about the experience you had. Years of experience has me taught me to not leave it up to one person. I assume your college class has a policy about "no late papers for any reason or you'll be marked down" (the high school my girls go to has that and it's infuriating). Anyway, if there is ever a reason you will be absent again, send the teacher an email, but also copy it to the dean of the department and the dean of attendance. In your email, make sure to say something along the lines of "as I have confirmation of when you receive this email, if I do not hear from you in blank days or hours, I will proceed under the assumption that this is acceptable." It sounds formal and goofy, but it works. I work with patients in research projects and if they miss an appointment we call, we mail a letter, then mail certified giving a deadline. It works. That way you have covered yourself. Why do you hate college?