Hi, guys. I'm Brazilian and new here. I'm not expert in english so I'm sorry about the grammar mistakes I'll make. Like everyone here, I really need help with this. I'm 21 and 7 years ago started to feel B12 deficiency symptoms. In all my life I used to have really good memory, atention e capacity of concentration, but it changed a lot since I started to feel this deficiency. It was gradative. In the beginning I started to forget some names in conversations and things like this. After that, I lost a few of attention capacity e then concentration. I couldn't wake up early, it was too hard for me. I searched a lot and found out I had b12 deficiency. I went to a neurologist, but he said I had nothing. I started Mechanical Engineering and had a lot of problems in college, but when I was finally ready to overcome all this problems caused by the deficiency, I got worse again. I felt really bad, even knowing what was happening to my body. I looked for another doctor, he said I didn't have b12 deficiency and prescribed folic acid and antidepressants for me. I've never taken it, except the folic acid. After that, I decided to take b12 injections by myself. I started with 5000 mcg weekly, but it didn't work fine because I wasn't doing it correctly. Then, I did some exams by myself, like Homocysteine and Metilmalonic acid. The first one wasn't to high, but the other was really high. From this moment, I was sure about the deficiency. I went to another doctor and he didn't know anything about it. After that, I started to read english articles about b12 treatmet and started to inject 1000 mcg daily for one week and then weekly for one month. One week I started the treatment, I felt really amazing. I felt it was me again for about two weeks. But, gradative some symptoms started to come back again. I started to take folic acid 5 mg daily and felt better again (I've already taken 14). But one month I started it, I was back to square one, feeling all the symptoms again. One week ago, I took an injection and feel better, but now I'm not fine. My iron and potassium levels are good, I took exam some weeks after I started the treatment. Again, I'm sorry about the language mistakes, but I need help. What should I do? What do you think about it? Thanks, everyone.