It's not unusual for drugs, that have been so effective, to just stop working, Twink. You sound like you are back where you were before. Perhaps a new med of a different kind. I've never tried P or N, because I know that all *uppers* cause me anxiety and heart palps.
I find that Prozac gives me a little boost, even after the 5 years I've been on it (40 mg), while keeping the depression and dulldrums at bay.
Tell your Doc the darn stuff isn't working anymore and tell him/her you need a battery charge..