Tara,
Two thoughts. You are due for a retest at four months and you may be feeling extra bad because the supplements are no longer right for you. My friend was in the four lows and at about 3-4 months she started feeling really fatigued, she retested and had moved out of the four lows so the supplements were too sedating for her. Once she switched to her new protocol things got much better.
Second thought- if you are still in the four lows this is very normal to have times of feeling really terrible. My first four months in the four lows were pretty rough. I felt I had absolutely no ability to cope with stress because my body was so sedated by all the supplements. Because I had little ability to cope with stress I had a very difficult time when something quite stressful happened in my life and I pretty much fell apart for a little while. Looking back I realize my body was just so exhausted and I couldn't do stress in any form at that point. But I survived and things got better shortly after.
I'm still in the four lows but I have gotten much stronger regarding dealing with stress although i still guard myself from too much of it.
Do you know about the NB support group on Facebook, it's a wonderful resource if you're looking for more encouragement!