You are doing great! To be an adult with a family and work and still practice that much, and learn a lot of music in a big push like that, is really good. I think if your teacher had given you such short notice to perform from memory in a concert, that would be very stressful and just too much. But since it's to perform in a lesson, he's probably just looking for ways to push you and see what you can do. And, as others have suggested, tell him you were nervous to play for him. Then tell him that you've been working hard and you know you can do better. Not apologetically, just matter-of-factly, like you're not freaked out by it, you'll just try again today. It helps to calmly believe in yourself out loud. It's all about recovery, right? and the journey, and what YOU bring to the music and the lesson. I bet the next time will go much better. By the way, there have been great discussions on this board about how different people memorize. You might enjoy a search on that. When I was younger (back when), I memorized by accident, just playing through my pieces-- and not all that many times, either! Sigh. Now I find I need to be more specific, but if I have a plan, I can still do just fine. So maybe if you take up just a few new memory tricks, it will firm it all right up. Best of luck, and way to go.