I don't have much energy and always feel kind of sleepy, should I start drinking ingesting some caffeine?

Well, it could be that you have an iron deficiency, which clifies you as anemic, or you could just not be getting enough sleep. Most people need eight hours of sleep a day. Try taking a short midday nap and if you don't already, take a multivitamin. Also, perhaps try drinking more water throughout the day. If the problem doesn't clear up, see your doctor to test if you are not getting enough iron. There are multivitamins that include iron, but since it irritates the stomach in some people, I wouldn't advise using them without a doctor's say-so.