So... After getting 5 MRI's done, the doctors determined that I have a blockage of some kind in the left ventricle in my brain. It is dilated to over 5 times the size of the right one, and is causing me to lose my eyesight, hearing, and coordination. It also shifted the centerline of my brain a full inch to the right. I am going in for corrective surgery tomorrow morning. It still doesn't explain the severe back pain and numbness, but it needs to be corrected sooner rather than later. Wish me luck.