I have been diagnosed with Vitamin B12 and Folate deficiency about 18 months ago. After initial boost of injections, I receive injections once every 12 weeks and take folic acid daily. 3/4 weeks after my injection I feel extremely tired and light headed again and its like my brain is made of cotton wool. I have memory loss, do strange things and would be very clumsy. Should I go back to my doctor and request more frequent injections?