Same happened to me, more or less. I completed it and didn't felt the impact at first as to why people were regarding it as even better game than the Dark Souls franchise. Then I let it gain dust for about 2 years.
The day it came on the Plus I told myself I should at least try and get the platinum now that will be packed with noobs I might get interested again. And so I kept playing with the same character I had created that was packed with goodies and made my life easier in NG+. Just by replaying it I actually did start enjoying all of it, from the lore to the environment. It's a lot grimmer than Soul series, but from a single player experience it is really much more rich and compelling. The difficulty in the dungeons is also a new layer of fun, however it can be grindy sometimes.
Later I purchased the DLC and since then I've been cooping with a NG character because the bosses are actually a lot fun there. I haven't had much fun in DS3 because of how everything feels so PvP related these days and I fell out of love for it since the first Dark Souls (and because it lags a lot too for me). But my advice would be, find your poison. Not everyone will like the mood of the game because it's too bloody, but the lore should be a very good thing to keep you tuned in or the amazing set of weapon (DLC ones are superb).
Here's how I would place it on a list next to the other games
Dark Souls 1
Demon's Souls
Bloodborne
DS2
DS3
Last edited by fluky-nintendy - on 28 April 2018