Suggest Treatment For Nerve Shocks

I am 43 years old and am 5 7 in height. I get nerve shocks and it is very painful. I am not able to sleep at night. I just got my serum B 12 blood test done and my B 12 count is 100. i am taking eldervit 12 thru Intravenous. pls advice as to how many shud I take. Which is more effective IV or muscular injections. Is there any cure for nerve shocks. At thhis level du u think a lot of damage has been done to my nervous system..? Is d damage reversible? Pls help