I need help fast! My beautiful bonsai, a miniature 12" Jade like tree is dropping it's leaves fast. I've had it for 2 months & watered it by filling the sink then letting the water overflow into the ceramic pot about every 7 days, then stretched it out to 10 days on advice of the gifter. Fed it once a month with N 0.005%, P 0.01%, K 0.02%. It lives indoors with indirect light from nearby windows. I've noticed it has "granular, brown residue" coming from the pebbles as though a worm in the soil is leaving it's deposits in 2-3 places. (It started in 1 spot) Is it a worm infestation, lack of direct light, or ??? The plant look sick & I hoped to succeed in keeping this one. Thank you for your help.

Your watering regime is totally wrong. You must not water to a schedule. I think you have been over watering, What pebbles? If they are under the pot and you are standing it in water, then that especially with this species is not good. There is no worm in the soil, the deposits you refer to are nothing. Stop the fertiliser.
Wait until the soil is almost dry then water. Do not stand in water, water from the top. Use a chopstick to check when the soil is getting dry.