1. That is normal, ask a doctor if you think you have problems and STOP FUSSYING AROUND ABOUT FAMOUS PEOPLE. You are doing fine, they just had more luck in life than you. I'm in the absolute 0.01%(or 99.9%?) of a normal distribution of my peers in terms of success and I'm nowhere near Elon Musk. You can be very successful, and yet, it won't be enough for you to be remembered or noticed. Why is that so important? I find this kind of questioning quite immature to be honest. Just focus on YOUR goals and YOUR strenghts/weaknesses.

2. Rest and look for people that can help you out, or solutions. Life is tedious and hard, we must fight everyday. If people respect that in order to grow your muscle, you must relax and chill when you have fatigue, why shouldn't you when you have mental fatigue?