I experienced the exact same thing as Scarlet.
Befor eI had my amalgams removed I used to go for a vitamin B12 - Bcomp injection that would really give me a boost, at times id be desperate to have them, just for the energy etc.

After I had my amalgams removed and before I knew that "we" should avoid it I went for my usual injection... I tought i was losing my mind, clung to my sanity for dear life for about two weeks before it subsided, Im 100% sure that it was the culprit, now, im petrified of the stuff. Stay away.