Is it permissible to think about suicide or to pray for death due to a physical deformity that causes psychological suffering, and do you advise undergoing surgery to get rid of it?

The questioner is congratulated on his contentment with Allah's decree and destiny. He should know that Allah has profound wisdom in His command and creation, and that great reward comes with great affliction. He is permitted to undergo surgery to eliminate the disfigurement, in order to remove an unusual defect, especially since it has caused him psychological harm.