hi..variation in alternate day in such a cyclic fashion is uncommon..probably its due to fatigue out of which you are performing poorly on the very next day..otherwise considering this history, I cannot stamp you an ultra-rapid cycler bipolar or like that..so try to change your life-style and work moderate..let's try..have a good health..

Your variation interval is too short otherwise It ca be dagonesed as a BIPOLAR DISORDER- where samething happen but in the interval of few weeks to few months.
Anyway cyclothymia may be a option but for confirm diagnosis more detailed history and information is needed. What is it?
Let me explain.
This sort of anxiety and depression occurs due to imbalance in the Neurotransmitter (Chemicals that act on nerve and brain). Several social factor like unfortunate events, problem in relationship, history of past bad events, your surroundings as well as medical condition may contribute to this abnormality of chemicals.
just go to a General Physician and he will show you the right way to live a healthy life.
Best of luck.