Missing

I've lost people in this life. Loved ones who have passed over.
I miss them....but I know they loved me....I know that they know that I loved them...and I am sure that their love stays with me, in my heart. They stay with me.
I have never lost someone I love, who is still here on this earth, but is simply lost to me.
It's a grief you can't really grapple with, can't come to terms with.
To know there is someone at the other end of the press of the send button that you really, really want to tell something to...really, really want to ask a question of...really, REALLY want to know if they're OK.
But you can't.
How do you get through that? How do you move on?
Bleeaagh!