There are days where you will feel uninspired, discouraged, and even lost with your training. But you are not alone. I have been training most of my life and I can tell you this; I HAVE DAYS WHERE I FEEL THE SAME, and it happens more often to other people than you think.
The trick is not to beat yourself up about it. Rather, forgive yourself and understand that you are not alone in your feelings. The highs and lows are all part of the journey.