Do not stop mentioning God just because your heart is not present. Forgetting Him completely is worse than being inattentive while you are mentioning Him; perhaps He will elevate you from being inattentive to being attentive, and from being attentive to being fully present with Him, and from being fully present with Him to being fully absent from anything but Him. [This is not difficult for God - Quran 35:17].
Now be silent. Let the One who creates the words speak.
There is no love greater than love with no object. For then you, yourself, have become love itself. - Rumi