I hate that “missing of a family unit" thing; missing the familiar energy of those folks who have become a part of your life, therefore, yourself.
It doesn’t matter if they’re jerked away through break-up, death, even growth. It hurts to lose the little traditions and the knowing of one another's needs and habits. The "going away" of that sucks.
This thing “family” can take any form. The common denominator is oneself.
Then, there's the "starting over" bit. Hate that, too. The waiting for new love to grow, the learning of new quirks, new preferences.
What is one to glean?