The question of fasting, is it required, how to do it, etc., comes up quite often. As Christians, we have no requirement to fast at any given time or period of time. You may set a length in your prayers or not. It seems better if you not. However, make sure you understand that fasting does not include going without food or drink for long periods of time. It is the deprivation of all that is pleasurable and comforting to the flesh.
Daniel 10:2-3 In those days I Daniel was mourning three full weeks. 3I ate no pleasant bread, neither came flesh nor wine in my mouth, neither did I anoint myself at all, till three whole weeks were fulfilled.
Fasting is show the Lord that what you are asking means more than yourself. Sexual intercourse is something that is curtailed during fasting.
1 Corinthians 7:4-5 The wife hath not power of her own body, but the husband: and likewise also the husband hath not power of his own body, but the wife. 5Defraud ye not one the other, except it be with consent for a time, that ye may give yourselves to fasting and prayer; and come together again, that Satan tempt you not for your incontinency.
Fast is to show God that what you desire of Him means more than the comfort and care of your flesh. The Lord may test your resolve.