I went through a rough period of being very despondent from about 40 days sober up to to 90 days sober, at which point I started feeling dramatically better.
I understand this period is sometimes called "the wall" and is not unusual. Apparently this is a symptom of the long-term healing going on in your brain.
Everyone told me it would get better if I kept taking it one day at a time, and they were right.