He hasn't been eating because you did not have a proper UVB tube, and this not only completely blocks them from absorbing any nutrition, vitamins, or minerals, but it also stops all appetite. You had a compact bulb sitting on top of a mesh lid and something else it was sitting on, and he was getting absolutely no
UVB light and he already has MBD, so he got none of the Calcium you were giving him, and all of this compounds into no appetite and depleted fat pads.
What UVB tube did you buy? What brand, model, strength (T8 or T5) and length, and what long fixture did you buy to put it in? And do you have it sitting on top of a mesh lid or is there anything else between the open, exposed UVB tube inside the long fixture and him while he's basking? And how many inches away is the UVB tube from him? Not only do you need to buy an adequate UVB tube and fixture for him, but it must be mounted correctly and within the correct distance from his basking spot for it to be effective, that's why we need to know what UVB tube you bought, so we can make sure you have it set up correctly.
His fat pads will restore themselves and his MBD symptoms will lessen once you get him an adequate UVB tube and fixture, and it's set up correctly, because this, along with correct temperature ranges within his enclosure, will bring back his appetite quite rapidly.
And did you check to be sure there is no plastic shield on the fixture that could also block the uvb ? Some of the Zilla fixtures come with a clear plastic shield in front of the bulb which needs to be removed, some buyers don't realize that.
