Definitely not oxidized. Yeast will drift up into suspension in the beer during fermentation due to Co2 bubbles and yeast activity - which is what the white hue is you saw during fermentation. When it's done with its job or the environment has become too toxic (no o2 or too much alcohol), the yeast will drop to the bottom of the fermenter and go to sleep or die, which is what you see in the darker beer. Totally normal.
General advice; don't fuss with the beer until you see it in the darker state you see and bubbles in the airlock have stopped. There is huge debate on when to add dry-hops, do what works with your schedule, just don't leave them in longer than the recipe states (this will give you vegetal/grassy flavors).
Another note is don't worry how long fermentation takes - the yeast will work at the pace it wants depending on temperature and strain. I recently brewed a cream ale with WLP001 (common for Pliny) and it took almost 18 days to reach true FG. It looks like you have a temperature control setup, to me, a tilt and Brewers Friend are THE BEST investment you can make. Wait til the gravity flattens out and keg/bottle when time permits for you.
Cheers!
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