Overwatering? Or something else

In your "torture" conditions, it's still resisting and wants to live! Yes, let it dry out, don't add calcium, you've already added enough for sure! Check the runoff ppm with the next watering with a new pH! Runoff ppm needs to be checked every time you water in soil! You don't know what's in your soil and how much of it, you need to find out the runoff from the drainage! If the plant survives until it dries out, then do what I said! If it dies within a day before the changes in pH and feeding, then start with a new plant! But don't make the mistakes you've already made in the future! 👆 Good luck, buddy! ✊😇