Not how it feels

I wish I had the words to tell you just how lonely I've become.
I wish I could somehow explain this emptiness building in my bones.
Are there words that can conjure how this feels? Is there an expression?
A turn of phrase?

It's a lie, it's a lie. I'm fine, I'm fine. I'm alive, I should be happy.
But I keep feeling that, somehow, I've come full circle and this time
is for keeps. It's a devastating compromise and I can't help it but I'm
falling into a wormhole and I'm not sure how to escape.

I should be over the moon with excitement, with joy and happiness.
I should be happier than any girl has a right to be. I have everything
I could possibly want, but I'm not content to let things lie as they are.
I was born to soar and I'm still walking uphill.

I keep telling myself that this is a phase. I'll get over the urge to jump.
I have no worries, nothing to bring me so far down, but I'm still living
in a dream, a dream that doesn't stop when I wake. And the storms that rage
inside my head, the monsters that shatter the sky with their lightning just
keep playing inside of me. I wreak havoc on myself.

I'm happy, so the other shoe is waiting to drop and I'm holding my breath.
Everything is going well and I am terrified. I'm fine, I'm fine. It's a lie,
it's a lie. The same song keeps playing and I'm still waiting.