Hi. I'm 34 year old female. Was told yesterday my B-12 in extremely low. Dr wanted to start shots right then I said no out of fear. I also have low vitamin D and low iron. I'm so afraid to take B-12. Will I shake or feel like I'm out of control. I have suffered with anxiety panic attacks and depression for years. I had my last 6th child a year ago. I can't be unable to help them. Any advice?