Fasting from words, fasting from a volume of speech, being willing to humbly accept the yoke of silence and quietude deprives the tongue of the mastery of our hearts and minds. The tongue is a very useful tool for the art of love and for the art of prayer, but it is also the means by which we afflict others and even our own selves so often. So it must be called into holy obedience.
There is a moment when you realize that you are going to have to die in reality, not just pretend to die. Not just read about dying, not just recite Rumi late at night, but really, day by day, hour by hour, moment by moment, go into the darkness of the Love of God and really surrender, a moment when you realize that to do that, you will need Divine courage.