Visual Disturbance
The numbness after my daughter's birth was also accompanied by a sort of tunnel vision where the peripherals were not blacked-out, but obscured by a sort of crystal-kaliedescope affect.
As a child, I once had an episode of traveling numbness. From one toe, across my foot, up the entire side of my body (down one side of the arm, across the fingers, back up to the shoulder), across my face (including one side, then the other of my tongue), and down again, until it ended at the toe where it had begun. No one knew what it could have been, or if I had only imagined it.
After the (vaginal) birth of my third daughter, I lost a lot of blood with a retained placenta. I had a constant but bearable headache, but had other things on my mind. Two nights later, I woke up with a numb arm. I thought I had slept on it wrong, but then the numbness travelled up to my face - across one side, over my scalp. I remembered the childhood episode so I didn't panic, but we did call the paramedics. Long story short, the hospital did every test under the sun, but all they diagnosed was anemia. I got a single-unit blood transfusion, and all the symptoms vanished.
A couple of times since, I had the beginnings of numbness in one side of my tongue or face, but it was usually when I hadn't eaten for a while. Iron-rich foods helped get me back on track, and now I take a double dose of iron supplements, daily.
From past, regular blood donations, I know my normal iron levels are a lot higher than most women's, so when the hospital discharged me at "borderline", that was extra low for my body.
I don't think you are going crazy and this is NOT any anxiety; definitely a Neuro problem. Hopefully you will get some answers from the MRI.
Was the birth vaginal or a c-section?