He was the source of life , healing and blessings and the prospect of crucifixion along with the curse would be abhorrent to Him and His nature. It was not that He was afraid, but this was so foreign and repulsive (like sin) that the only way He could endure was to be assured it was His Fathers will.
Why pray to avoid the Cross when He knew He was sent to other for that very purpose? He had forewarned the disciples. Are we saying that the Lord is telling the Father, I didn’t know what I was getting into? That analysis doesn’t add up.