thank you, to solve this endurance problem, i started exercises with my arms and wrists. I lift weights and arm wrestle with my friends, interestingly I can say that it reduces my fatigue
If you get physically tired from playing the earlier parts of the piece it's a technique issue. You should not get tired at all. I don't think there is a quick fix, you need a teacher who knows their stuff to take a look at your technique and help you change it.