Maybe one day you can find somebody, or someone, who will not take the place of her--because she is irreplacable--but perhaps they can at very best, or worst, (not necessarily, as you say: "fill the void," either...) make-up for some of that. The absence, and the lonliness, and the sadness with which you feel. You may not be able to feel it now, or even in the very near future.
But there may come a time, when you are ready, and that person comes into your life, and the time is just right, to take a chance on that which could make things a whole lot better than they are now. Again, not wipe-away anything, or engage in any sort of (unfair) comparison - b/c it is unlikely that anyone will ever live up to that (given how much they meant to you).
Though, we don't always need to hit the home-runs, or win the power ball/lottery. Sometimes, we can (not settle; but accept & admire) learn to appreciate, and to respect what we do have, and what is possible--as opposed to what we don't, and what isn't. Or you can feel & be 1000% entitled to disagree, vehemently I might add! And I'd take zero exception, or offense~ (for I am not You/& I have not lived through what you've been through). : ) Just (merely) trying to lend a "helping hand!" Peace, B~
Post: If lonliness, in & of itself; & that is to say - on the surface - is not the problem/or the issue. . . then there is still this sense of 'yearning,' for a special connection that is missing. I'm reminded of the old saying, "Whether you think, I can't or I can't... either way, you're probably right." :^) And that's not an, "I told you so," or any-thing.