Scheduling issues have me going insane

I have a doctor's appointment (that I shouldn't have to be having) because I need medicine, but they won't give it to me. I scheduled it a month in advance because they wouldn't give me anything sooner. Now I'm discovering that I scheduled the appointment during one of my classes (I signed up for the class after I scheduled the doctor's appointment), and I have to reschedule... If I have to wait even a day longer than what I'm already being forced to wait, I might scream.