What Causes Severe Headache And Chills Along With Weakness In The Legs?

Two weeks ago I ended up in the hospital with weak legs, severe headache, felt like I was going to pass out and shivers. The did a CT scan, urine test, and blood work. Nothing came up. I followed up with my primary and she tested for lymes, lupus, thyroid, vitamin deficiencies, SED, rheumatoid, thyroid antibodies, etc. Everything came back normal except my Vitamin B12 was 297. I started taking vitamin b12 pills for the past few days. I am nervous for my neurologist appt Wednesday because my legs are still weak, my headaches are bad from temple to temple, I sometimes get pins and needles in my fingers, and occasionally dizzy. In the past I was diagnosed with chronic tension headaches but this time around I am having issues with heavy legs. Im nervous. Do you have any ideas what this could be?? I am very busy with grad school and working full time so I am hoping this is just stress.