It was so bad that even his father burned his back.
His Father did not 'burn his back.'
Jesus felt as though He was forsaken, because Jesus was fully human (while also fully divine), and did have anxiety and doubt. His suffering means nothing to us unless He suffered as we would. That is why we need not be anxious or doubtful, He took those for us.
This all being part of God's plan to offer us salvation, how could He forsake himself?
Or maybe I misunderstand your post.
I believe that should have read "turned his back".
As to the rest of your post. How do you know this?
Bible study, except my last question, which is logic. God can't actually forsake himself.
