"I'll miss you" is not deep enough

"i'll miss you" is what I should say
I still can't accept that u are moving away
In my head I know your reasons why
But in my heart I feel a piece will die

I'm watching the pieces of me fall
Feeling there's nothing I can do at all
I should probably stop standing still
But I can't conjure up the will

In my heart you filled up so much space
Now deep emptiness is here to take it's place
My mind is slipping and I fall inside
Into such a dark place I wonder if I'm even still alive