Sounds fungal. I can't really see much from your photos, but they are generally prone to fungal infections. Baking soda and milk, neem oil, peroxide, copper fungicides. Any of those will help with prevention, but once the damage is done, the plant won't heal. The spots will persist. I'd remove what you can of the worst of the spotted leaves, and then do regular (you have to be consistent) treatments weekly to prevent.
I am getting good results with 1/4 cup neem oil extract and 1 heaping tablespoon of baking soda in 2 gallons of water weekly.