What Causes Increased Free Water And Ischemia In The Brain?

My brain MRI shows gliosis, increased free water, ischemia, and demyelination. I am a 38 year old female. 5'3" and 245 pounds. I have hypothyroidism, and high blood pressure. I haven't had a head injury but I have a very bad memory. This started because of a swollen lymph node in the back of my neck and a bruise-like sore area on my head. Any ideas? I am being referred to neurologist. How concerned should I be?