Did I ruin my cartridge or my stylus? Or both?

Possibly the stylus only.

I can't see how the innards could have been damaged.

I've on occasion managed to lower my cart onto the felt mat of my turntable without any obvious issues thereafter.

At the Radio Station where I used to volunteer, the cartridges were subjected to all kinds of abuse without breaking.

It usually took something catastrophic to result in the station having to fork out £30 for a replacement stylus (mid 90s prices).

Anyway, I was sad to read of your misfortune.

That really was unlucky, but before doing anything I'd give that sylus a really good clean first.

It could be that some vinyl/gunk became welded to the stylus.

Perhaps someone could chime in with the best way to safely deep clean the stylus?

You should invest in a 10x jewelers loupe. It enables you to see the stylus much better. I say 10x as it is still relatively bright. The higher magnifications limit the available light. I'd say that upon inspection, and no visible damage seen, I recommend cleaning the stylus with a wet clean stylus cleaner, such as the one made by audio technica. 

I’ve played more than my share of wretched, ancient, filthy vinyl in my days. And sometimes the needle and cantilever would look pretty dirty afterwards. In any case, I’d clean it best you can. Did the cartridge come with a stylus brush? Did you ever buy a bottle of stylus cleaner, like Stylast or Tweek? If so, give it a go, but if the brush is the least bit stiff only go back to front!!! In any case, chances are decent the cartridge/stylus will become usable again. Mine always did. A small watercolor brush and distilled water might work, too. With this combo, you don’t have to just go back to front, either.

The stylus assembly pulls out of the MM cartridge body. Yank it out, have a good look, it’s possible the stylus tip is ok, but you got gunk along-side the cantilever as it recedes into it’s housing, that would make it sound muddy, clean it out, back in business.

I keep this 3.5" diameter mirror, 20x magnifier, on the plinth below my cartridge when at rest. Very easy to view the underside, tilt it, view from various angles. I aim a nearby light at the mirror, it reflects up making it very easy to see everything.

This is another reason a removable headshell is an advantage. Especially if you gunked up a MC cartridge with non-removable stylus.

I will add, if it is ruined, rather than a new stylus for it, I would take the opportunity/advantage to upgrade to a cartridge with wider stereo separation and tighter channel balance, I think the AT540ml is a good choice

a similar sound with far better imaging.