You should make an appointment to see your primary care doctor
as soon as possible for help sorting this out. Fatigue that is persistent like this really needs a medical workup to make sure it is not caused by something serious or treatable.
Many case of low energy are caused simply by high levels of stress, and lack of sleep. Your doctor can help you take a look at the various things that are going on in your life to see if this might be contributing and, if so, help you figure out how to make some changes to reduce stress and improve sleep.
On the other hand, if there aren't any life stressors causing your fatigue, there might be several different medical conditions that needs to be ruled out. For example, depression
is a very common cause of fatigue or low energy levels, and it can be easily diagnosed by your primary care doctor and treatment with an effective medication begun. Similarly, various nutritional deficiencies, such as anemia
from low iron levels, or trouble with the thyroid gland may cause fatigue. These conditions are easily diagnosed with simple blood tests and, in most cases, they can be remedied quickly with medications.
Get in to see your doctor as soon as possible!