Amazingly, we have a sort of religious debate here without any rancor, and you and xzins have both made excellent points. Fasting does raise the question on whether self-induced suffering is something to be sought after. But fasting, as you mentioned, is a type of self-denial rather than an active means to induce pain. I am not able to recollect any instance in the scriptures where the righteous actually inflict physical pain upon themselves, but many instances where, for a righteous cause, they endure pain inflicted by others. Jesus certainly allowed the nails to be driven into his hands, as he could have easily called upon a legion of angels at any moment to overcome his tormentors, but I don’t see this as self-inflicted suffering even though it was self-permitted. Also, the suffering on the cross had an underlying purpose, as it was a means to bring salvation to a world of sinners. In a similar, if infinitely lesser example, someone undergoing a painful recovery after an operation to donate a kidney to a loved one is enduring a self-permitted type of suffering, but the suffering is for an underlying purpose, and is not done simply for the sake of the suffering.
"Jesus certainly allowed the nails to be driven into his hands, as he could have easily called upon a legion of angels at any moment to overcome his tormentors, but I don’t see this as self-inflicted suffering even though it was self-permitted. "
Not to ridicule. Just to point out what you just said. Remember not only was he the victim like the Lamb of the Old Testament but the High Priest offering the victim. So he is offering the pain and suffering as a God can with the resources of a Deity. Which is through the people who did it to him. It's more complex than it seems.