Final answer:
The student may be experiencing bipolar disorder, which is characterized by extreme mood swings between mania and depression.
Step-by-step explanation:
The student in the question is describing symptoms that indicate they may be experiencing bipolar disorder. Bipolar disorder is characterized by extreme mood swings, including periods of extreme happiness (mania) and periods of extreme sadness (depression). The student's episodes of extreme happiness and increased energy followed by periods of feeling down and tired are consistent with the symptoms of bipolar disorder.