It might be hard to figure which was the most torturous part for Jesus pertaining to His sacrifice at Calvary.
Jesus was betrayed, some of His best friends acted like they didn't know Him at the time, Jesus had been falsely accused and convicted, beaten, and physically tortured in myriad barbaric ways.
It is difficult to imagine that anything could be worse than to be nailed to wood to die over the course of hours in such a horrific way.
Jesus is love. To love, as Jesus loves, and to get what He received overall in return, I can't personally imagine greater suffering.
God loves those having ingratitude, and commands His children to do the same. If someone only helps the grateful, then they would only be giving to receive, living as a false god for their own glory.
The world has never known such love as at Calvary, a sacrifice of love leading to justice, judgment, and eternal life.
John 3:16 For God so loved the world that he gave his only begotten Son, that whosoever believes in him should not perish, but have everlasting life.