Hi I was just wondering if you could help me, I'm 20 years old (female) and I've been feeling really really tired (exhausted) recently. For about 3 or 4 months. Menstral cycle has been normal and I know I'm not pregnant. But I've just constantly been tired, out of breath, little dizzy, very thirsty, urinating extremely frequently, having mood swings and sometimes really feeling like I need to eat a lot. I also get really bad cramps in my legs and an aching pain in my lower back on mainly my right side but sometimes my left. What is wrong?