It is a profound and honest thing to name that feeling, and I wonder if that very sense of absence might actually be a kind of presence — a sign that your heart is already reaching toward something it was made for, even before your mind has words for it.
Saint Anselm gave voice to this exact experience centuries ago, praying from the depths of that same hollow: "You have made me and remade me, and you have bestowed all good things on me, and yet I do not know you. Finally, I was made to see you, and I have not yet done what I was made for. O miserable lot of man, when he lost that for which he was made! … He lost the blessedness for which he was made, and found the misery for which he was not made. … Alas, we remain empty!" [3]. He did not see that emptiness as a failure or a flaw, but as a testimony — evidence that the soul was shaped for a fullness that nothing else can provide.
The Second Vatican Council affirms this same truth with gentleness, teaching that "every person remains for himself an unsolved question, obscurely perceived. No one can entirely escape this interrogation, especially in the major events of life. To this question only God fully and with all certainty provides the answer, who calls man to higher thought and humbler inquiry" [6]. Your questions, then, are not obstacles to finding God; they are the very path by which he invites you closer.
I wonder if you might let that feeling of missingness be, for now, not a problem to solve but a quiet companion — one that whispers of a love that already knows your name, even as you search for his.