wondering about b12 and low feritin

about 9 yrs ago I had almost a year long episode of wierd symtoms (symptoms). Burning tingling and numbness in arms, legs and face. Extreme fatigue, pain in legs, twitching fingers, cramps in feet etc. MRI, Neurologist, etc with no conclusion. Over the next few years symptoms diminished. Laast year, I began having flight or fight issues...I had significant increase in adrenaline and my heart was beating faster..like I was afraid or had been frightened. I was under alot of stress in my executive position, to the point I resigned. I was also losing weight and feeling cold alot. I was going to weight watchers so the loss was intentional. Doctor told me my B12 was 270 and my ferritin was 5. SO over the past year, I definatley improved which was due on part to less stress, b12 shots and ferrous sulfide supplements. I recently started feeling the flight or fight thing again, waking at night with my heart pumping and feeling startled. ANd the scariest part for me is the tinlging and numbness is back. Im off balance, and losing memory. I cant remember alot of things. My kids are frustrated with me and im feeling very compromised. the b12 level went up a bit after shots, but the ferritin stays down at 5. I have lost 64 pounds this year...the last 30 with very little effort.

Any suggestions for what direction to head with my doctor? They just keep saying I need vitamins but I want to know whats causing the low feritin and the memory loss and confusion.