The human body and brain were not made to endure some things easily. Some of the procedures I underwent fighting cancer were without appreciable anesthetic. There are times when I still wake up sweating, remembering those moments. The human mind and body do not want to experience pain and they descend into an almost animal level, a feral ferocity that robs of us pride, hope, and ability to claim our own self. All that is left is survival.
I am sorry you had to endure this, but glad you will not again, hopefully, have to endure such.