Firstly I would like to thank you all so much for the advice posted. I feel better than I have done for years and it's all thanks to you and this site.
I had been diagnosed with possible menieres, because of the dizziness, vertigo, memory problems and even came close to major surgery and removing part of the back of my skull to make more space when it was discovered I had a slight chiari malformation. They said my dizziness and vertigo 'could' have been caused by the chiari. I stalled on the surgery and asked to be referred to a neurologist first who said it could be the chiari but many people go there whole life never knowing they had this and no symptoms-mine was only found when I had a scan to check my ears at my request because I had tinnitus and wondered if the balance problem could be middle ear issues and to see if there was a 'mechanical/structural reason for my vertigo/tinnitus etc. If this showed nothing I was ready to accept the diagnosis of menieres but instead they found the Chiari malformation which set me off on the route to have the surgery.
The point of telling you about that was I found your site. I found that many of my symptoms could be attributed to the under active thyroid I have (which still hasn't been tested by my GP for years) but more importantly I learned about vitamin B12 and vitamin D and decided to get my own blood tests through Blue Horizon. They were both very low which could have been the reason for my symptoms.
I've supplemented them now, stopped gluten and dairy and gone over to ndt and the difference is amazing. I was ready to have the surgery but now I'm better. No balance or vision problems. No vertigo or nausea. My memory and concentration improved no end. I spent nearly a year every day or two having 'attacks that started with visual disturbance, vertigo and dizziness resulting with me vomiting and staggering in my office it came on that suddenly. I kept having to be taken home or collected by my family. I had to carry plastic bags around in case it happened when I was out of the home or my office. I couldn't drive. This is why I was ready to have the surgery. But not now thanks to your information.
I may need it in the future but I'm going to carry on following you and taking your advice- it's what made the difference I am sure.
Sorry about the long post but I thought someone else may be in a similar position and it may help.