It was used in a lot of cases of depression that was not responding well to other treatments.
Problem is, it DOES tend to come with some nasty side effects
, once being exactly what you describe. This med was actually responsible for putting people into manic episodes, which is why it isn't a great choice for treating anxiety disorders, BPD, and the like.
Out of curiosity, have you tried other meds? Did your doc explain the thinking behind trying Tofranil?