Was tested for Iron overload ages ago (forgot to say) and that came back clear.
However MRI result has come back and they have discovered a tumour in the rear of my brain. No need to panic apparently despite being told its large. The neurologist will see me in early Jan to decide on course of action.
They are not sure if this is the cause of my problems or we have just stumbled across this by pure chance - and hence may be unrelated.
Time will tell.