Been lifting for 3 years now, and finally feel like I hit a wall in my training. For some reason my PR's seem to be getting lower, I don't have as much motivation to go to the gym, used to workout for a solid 2 hours, now I'm in here for 1 hour maybe. My muscles feel more lethargic than normal. My diet has remained the same, only thing different is I'm doing a tad more cardio. Is this just a lack of motivation? Is it my mind playing tricks on me?