[Major Tom]

Could it be a lack of sleep? Too much volume? Sometimes you have to listen to your body and take it down a notch. I find it helpful, every 6-8 weeks or so (depending on the signs I'm getting), to take a de-load week. This amounts to cutting back on the number of sets/reps, and using roughly 60-70% of the weight I normally use. Light enough to actively recover, but heavy enough to maintain strength/mass provided you're still getting proper nutrition (probably going to have to cut back on the calories to adjust for reduced activity level). This is the time I usually cycle off my pre-workout supplement and stimulants in general to get my body re-adjusted. Sounds like you work out first thing in the morning. Also, do you train fasted? Because if so, you should definitely be aiming to get most of your carbohydrates after your work out. Exercise improves your cells' sensitivity to insulin (like an extended fasting period), so it will significantly affect the way nutrients are partitioned and preferentially shuttle nutrients consumed in the post-workout period towards replenishing glycogen stores and repairing damaged muscle tissue.