Great writing, Nevena!
I always thought Peter slept soundly, because they were so at peace with dying. Like Paul says, " I am hard pressed between the two. My desire is to depart and be with Christ, for that is far better. 24 But to remain in the flesh is more necessary on your account. 25 Convinced of this, I know that I will remain and continue with you all, for your progress and joy in the faith, 26 so that in me you may have ample cause to glory in Christ Jesus, because of my coming to you again."--Philippians 4:23-26
Peter could have been thinking, "I get to see Jesus." Then, the angel was like, "Nah, you are still needed here." 😅 I have never thought about it the way you interpreted it, but Peter was human. So, he could have been having normal thoughts/doubts too. Lots to think about.