I don't think it's unusual in a seven week span to have a down day or two, and I don't mean those of us in recovery. I heard that even "normies" get down in the dumps occasionally.
I'm old enough to remember biorhythms and the cyclical nature of one's physical, emotional, and intellectual well being make perfect sense to me. Don't feel bad about feeling "bad." It will most likely pass. If it doesn't, it could be something more serious.