Here's a case study on how niacin can upset the balance of things. Even though your issues are different from the patient in this link, it's a good example of how quickly things can be imbalanced when you have one or more of the mutations.
Mrs. D suggestion to tested for MTHFR mutation is probably a good idea. It's all very complicated and knowing what you're dealing with can help you manage your supplements.
Glad you're coming out of this tailspin.
http://mthfr.net/overmethylation-and...dy/2012/06/27/