The information you have provided is not nearly enough to determine if this should be a concern for you or not. I have mood swings all the time. Mood swings are not uncommon. Generally speaking, most people experience some fluctuation in mood on and off. However, being depressed all of the time is usually a symptom that there may be something more serious going on and it is a good idea to see a professional for an opinion.
Mood swings can be normal reactions to everyday life.
However, if they are rapid or severe, it is a good idea to get a medical and psychological check up. Mood swings can be symptoms of a variety of problems for which treatment is available. The Stress Management Program at the University Counseling Center is a good place to work on establishing a healthy response to stress in your life. The service is available to students on a walk in basis in the basement of the C wing of the Clark Building. It may be a good idea to get a formal evaluation of your situation and your symptoms.