This is a good question and one that is best answered by your primary care doctor
or other medical professional. It is difficult to diagnose what is the exact cause of the symptoms you are having based upon the limited history you have provided, it would be prudent that you are evaluated by a medical provider in a short time span as this could be depression
or it could be one of multiple other causes. Only your doctor can obtain a good history and physical examination and obtain tests to help diagnose your condition and decide upon the appropriate treatment options available. In general, there are several causes for the symptoms you are describing which would include depression as one of the main options. If that is what you are diagnosed with, your doctor may have you try a low dose of a medication to help with your mood and hopefully this would help you. There are also several other causes for these symptoms such as thyroid dysfunction (which can be diagnosed with a blood test and treated with a daily medication), other blood abnormalities, or other psychological conditions such as post-traumatic stress disorder (PTSD). Only your doctor can diagnose the underlying cause of these symptoms.