As you probably know, ovarian cysts are very common. Their symptoms vary depending on the type (there are many types), and size. The best types of physicians to approach about this problem are either a primary care physician
such as a family medicine doctor
or internal medicine doctor
or a specialist such as an OBGYN.
Fatigue is a very complex symptom that can have many different sources. Ovarian cysts (depending on there source) can be a cause of fatigue. Other causes of fatigue include lack of high quality sleep, poor diet, little exercise, or a sudden change in daily activities. On the list of possibilities is ovarian cancer, something that can be sometimes associated with ovarian cysts.
I suggest that you schedule an appointment with you primary care physician first. This is because fatigue can be caused by something other than an ovarian cyst. He or she can take a more detailed history of your symptoms and perform a thorough physical exam. From there, you doctor may decide to refer you to a specialist. If your other symptoms (the "same problems" that you mentioned in your question) are pelvic pain or fullness, then it would be equally acceptable for you to start with an appointment with your OBGYN. Good luck, and thank you for your question.