I recently had the same issue with my Americana rooster. I thought the same thing he seemed truly depressed. So what I did was removed him to a smaller pen adjacent to the coop for a couple of weeks and started giving him plenty to eat and a lot of fresh water. In no time, 14 days he was strutting his stuff and back to his glorious self. He is back with his ladies now and doing great. Not sure what was wrong wether it was illness or he just needed a break and rest. But you might give it a try. I believe sometimes a rooster will wear himself down taking care of his girls making him easy to catch a simple cold or any illness. I was on the verge of thinking he was truly going to pass away and now I got my rooster back to normal. So you might give it a try. Good luck! I hope he comes out of it ok. I think he will.