I think its a good first step to realize no one can fill that hole.
Im working on filling it myself. For me that is a spiritual/meditation exercise. I am a living breathing creature, part of a massive web of living, breathing creatures that has existed and transformed for millions of years. I am not better than any other creature, but nor am i less. I deserve the space, the light, the air , the water as much as a lion, or a dolphin, or my neighbor, or a cedar tree. I am never separated from anything. Everything that lives shares my life, and i share the life of everything that lives. I do not need to be, or do, or achieve anything. Like the coyote on the hill behind my house, i already am. I already am filled with blood and breath. I find my wholeness in my connection to all of nature. My suffering is not unique. The world is full of the abandoned, the sick, the orphaned, the lost. Even in my greatest pain i am not alone. The world over, others are feeling it just as i am.
It works for me, but requires regular meditation and discipline and time in nature to maintain my sense of wholeness and connection.
The good part is once you FIND this sense of connection, short of the whole planet exploding, there is no way to lose it.