Stopped taking B12 pills due to my B12 being high .

I have been taking B12 for years. However due to the results of my last blood work my B12 was elevated quite a lot. Therefore I was instructed by my doctor to stop taking them. Needless to say I am not at all feeling very well.I feel so miserable it's frightening. Should I have given them up completely ? It was to my understanding you get rid of what the body doesn't need when you urinate. I would appreciate any help you could give me. Thank You