For the last few months I have been feeling really tired, I haven't been sleeping well. I was prescribed a course of sleeping tablets which I have now finished. I wake up exhausted even if I have been in bed for 9 or 10 hours. I wake up with headaches, I feel weak and my limbs are sore and aching. My back and hips are sore too. It feels like I have pressure in my head and fizzing in my ears. I'm very pale naturally so I'm not sure if I'm extra-pale. I'm at my wit's end. It's affecting my quality of life and I'm not able to do things day to day. What could it be?