what type of basking light are you using now. Also are you using an UVB light as well. We can help more with this information.
Beardies need heat (from above) to properly digest their food. Basking temps need to be correct. Temp guns are around $30 and up. Another option is a digital 'indoor-outdoor' thermometer--you can get these at Radio Shak or WalMart or even a garden center for around $10. DO NOT use those stick on strips as they do not measure the kind of temperature (surface temps) that you need. The small 'dial' types are also known to be unreliable. Basking area should be between 100- 107 (give or take a degree depending on age and care sheet).
If temps are too low the dragon will not eat as it should and will suffer because of it.
Offer a good mix of greens/veggies every day...they may not eat it at first but keep offering it. They need protein daily until they are a year old. Offer as much as they can eat in a 5-10 minute period 2-3 times a day. When our BD was that age he would eat about 30 crickets a day total. I know of another BD who ate more like 100 a day--it just depends on their personal growth requirements.
HTH
DM