Thanks for your question about your jade plant.  I think you've identified the problem--over-watering.  And now you may be stressing the plant even more by not watering it at all.  The problem with the initial over-watering is that the damage done to the plant's leaves doesn't just go away because the care is now different.  And, we can see the effects of this by the little white dots that are on the leaves, which results from guttation.  Here it is described:  

"Guttation is a process by which plants, usually under conditions of high relative humidity, cool temperatures and high soil moisture content (e.g. at night in a greenhouse), will express moisture through specialized structures called hyathodes to relieve some of the fluid pressure within their tissues despite their stomata being closed for the night.

These tiny droplets may collect along the margins of the leaves and run down to the drip tips of each leaf. Or, if they are too small to collect in that fashion, the droplets simply remain in place on the leaf blade where the morning and afternoon’s rising temperatures and sunlight will dry the droplets, leaving behind the soluble contents of the liquid, mostly xylem fluid rich in sugar and mineral salts.

While the secreted fluids themselves are not harmful to the plant, they may indicate faulty watering practices, such as watering late in the day or watering too frequently to allow healthy dry-down and aeration of the medium to occur between irrigations. The whitish deposits themselves are easy to remove if they become unsightly. A wipe-down with warm water and perhaps a bit of soap will take care of the residue."

Your plant's leaves show signs of lesions (the brownish spots), which are also indicative of the plant's reaction to the over-watering.  You're not going to be able to cure the lesions; they're there for the duration.  I suggest you follow the instructions for watering, etc., in this Clemson U. Extension article, knowing that you're going to have to live with some residual indications.  

I hope this is helpful for you (and your plant)!  Good luck.