What Causes Head Ache With Dizziness And Poor Memory?

Hi, I am very concerned as I have been feeling unwell for quite a long time now but in the last few months, I am getting more symptoms. I have been experiencing head pains in the back of my head (it also feels as though someone is putting pressure on it) which make me feel sick and also wake me up in the early hours of the morning. I have now started to feel dizzy, my memory has been terrible and I keep getting throbbing pain in my legs, spine and hips which is getting worse day by day and extremely painful. I also feel extremely tired especially in the mornings. I have noticed that I now have twitching in my eyes on some days and I can't stop emptying my bladder. I have also noticed that one of my pupils is much bigger than the other. Please can you help? Many thanks for your time, it's much appreciated.