Your mom might not know the term cyclothymia, or she might think you are being overly dramatic in diagnosing yourself with a mental illness. You can print out descriptions from a couple of different websites and highlight the symptoms that you have had. You can also start keeping a mood journal where you log your ups and downs. Write a short description of how it feels: I had trouble getting out of bed today, I feel ok, I feel hopeless, I feel like I love everybody. This might help your mom and your psychiatrist understand your patterns and the severity of your mood swings.