I feel you. Been there, done that, got the t-shirt.
Actually, I should probably have, like...a hundred t-shirts by now.
(Where are my t-shirts???) Anyway...

I know what you mean by the emptiness that's always there. I feel it on a regular basis. I mean, I do try to distract myself, and sometimes it works. But it's always there. Doesn't matter where I'm at in my day or what I'm doing, sometimes it'll sneak up on me. Like yesterday, I had an unexplainable wave of sadness just hit me suddenly, and for all the rest of the day I had that emptiness. I think mine is because of loved ones I've lost and wishing for things to be the way they were.

I'm sorry you feel it too. I know it's awful.
I do hope you feel better soon.