I think I know which ability you refer to, as my fear when I discovered this was that I couldn't work as a software developer anymore (before I got a grasp of what had actually happened, it took a while to actually understand the extent). I used to visualize arrays/tables/graphs in my head (like images/fancy animations) and do operations on them to imagine how one could transform them etc. But I also had/have a native sense of "depth" to data structures, which I also used. That one can move around in a data structure in a sense, I'm sure you know very well what I mean. Luckily that ability is still intact, which I've been relying a lot more on lately, but I can imagine you being much better than me on those kind of tools. The mind is so extremely fascinating, and it's so weird to think of the ways we think of things.

I tried visualization exercises (there's a lot more to the story that I didn't consider space to add here) and the first time they worked rather quickly, so I regained the ability in the course of days. But as I mentioned in another comment, I contracted covid again and then it was even worse than it had ever been and training didn't feel like it worked. I regained a little bit since that infection, but got covid yet again (it's an awful disease) and then it was back to square one. It seems like something in the brain had to heal before I could train it back up, but I'm afraid that the damage will be/is so severe that it will not be possible to recover (especially since I couldn't even create images in my dreams).

I might get better over time if I just stop getting covid, but as isolating myself is out of the question, that's unlikely to happen. Unfortunately it seems much harder to recover each time. Since last time it's not really been recovering. On the bright side, my sense of taste/smell has not been damaged again, which has been great.