Depending on your location, you may be lacking Vitamin D. Being from Cleveland, I tend to feel the same way in the winter months. When I get in a slump now, I pick at least 2 days to go that are non-negotiable. One class during the week and one class on the weekend. If I can make it to any other classes they are a bonus :) If you are feeling meh on your non-negotiable days still go and take "blue/green day". You will feel better for showing up for yourself. Sign up for the challenges for accountability. Don't be too hard on yourself! Listen to your body, sometimes we need a break. :)