She really needs a better UVB, coil bulbs aren't suitable especially for beardies. 12% T5 tubes are the best option. What percentage does she have at the moment?
Without proper UVB she won't be able to synthesise D3, that means any calcium you give her will do nothing - this is the main cause of MBD, and can also cause loss of appetite. Her trying to get as close as she can to the UV bulb is a sign that she's not getting enough, in getting too close she can seriously damage her eyes. I can pretty much guarantee that when you change to T5's you will see a huge change in her.
You can also up your temperatures a few degrees.