Well, there is a crowdfunded documentary (which I even funded years ago) whose name is based on the last episode of the show "What we left behind" and where you can see interviews with the cast and the original writers imagine what an eight season might have looked like.
It's nice and they remastered several scenes of the show in high definition, so it's worth a watch.
Then you can rewatch it over and over again. I'm doing my third rewatch right now. I have only rewatched TNG once and no other series is as amazing as DS9 to me (though I have rewatched several individual episodes across all series)
I know Andrew Robinson has written a novel about Garak, A stitch in time, which I understand is well regarded and Garak is such an interesting character that sooner or later I'll check it out.
We feel your loss, but you should celebrate because it was so well put together and it had a charm no other series really had.
Yes, seconding the recommendation for A Stitch in Time and it’s wonderful to hear “Garak’s” voice again if you do the audiobook. I also really enjoyed the DS9 documentary!