What are the symptoms of vitamin B12 deficiency?

Hello doctor,

I am a 22-year-old female, and I have been feeling unwell suddenly for the past four to five months. I have been healthy and well before then, I am experiencing symptoms like tachycardia and heart palpitations. I will be sitting watching TV and suddenly my heart starts beating like crazy, throbbing headaches nearly every day that barely gets better with pain relief, pain radiating to my neck and shoulders, numbness and tingling on ride side of my body, shaking and twitching in my hands, feeling very lethargic and tired like I have no energy to even go up and down my stairs, feeling very dizzy and lightheaded where I need to sit down, and I am having these weird episodes where I feel a sudden paralysis and numbness through my full body and feel like I am floating for a few seconds and it is a scary feeling and it happens regularly.

I went to the doctor and had blood tests where I was B12 deficient 157 was the number, I am also folate deficient, I have had five doses of the loading dose B12 injection and I feel worse than before. The nurse told me I should have been feeling some improvement by now, I am just worried In case this is something more serious. The Internet tells me this could be a brain tumor. I am terrified and I suffer badly from anxiety which is not helping. I just hope this is my body trying to get used to the B12.

Is this my body getting used to Vitamin B12 injections or something more serious? Please help me.

Thank you.

Hi Doctor, thank you so much for your reply.

How do I go about requesting these tests, as my doctor is not taking me seriously? They said it is anxiety related which has made me feel like they do not care and makes me feel anxious to make an appointment. I really want an MRI as this will help me to relax more.

Thank you.