Hi
I may not be expert but consider myself fairly experienced and do own a coffee.
>Misting- don't bother
>Rocks in the pot, those don't help and can even make it worse.
>Clay pot- can dry very quickly, can have less useful soil than you think, and especially combined with the rocks.
>Low light- what is your location and exposure? Light is really the food of a plant, it drives the whole engine; not enough light is like starvation.
>Is that snow outside? COuld those leaves be laying against freezing glass, causing patches of damage?
I would get a plastic pot just a little bigger than this one, get rid of the rocks, pot in good potting mix in the new plastic pot, give more light if possible, don't let it touch cold glass (if that is the case) and water a little more frequently.
The newer leaves look really good, I have hope for it
