In addition to the photos of him and close ups of his face, as well as photos of his enclosure and his lights, can you list what brand/model/wattage and type (compact, coil, tube) of
UVB light you have, and the same for your basking light? What size is your enclosure (dimensions or gallons)? And are you using a stick-on thermometer to take temps, or do you have a digital thermometer with a probe on a wire?
Your temperatures are way too low, he cannot properly digest his food or absorb any nutrients being that cool, and I'm going to assume that you're using stick-on, round or aquarium thermometers, which are usually off by up to 20+ degrees, and which you cannot use to measure his basking spot temperature. You need to go to Petco, PetSmart, or any pet shop with reptile supplies and spend $10 on a digital probe thermometer to accurately measure his Basking Spot, Hot Side Ambient, and Cool Side Ambient temperatures. You need to get his Basking Spot temperature up between 100-105 degrees, his Hot Side Ambient between 88-93 degrees, and his Cool Side Ambient between 75-80 degrees. You must always allow the probe to sit on the spot you're measuring for at least 20-30 minutes BEFORE reading the temperature, and do this every time you take a temperature.
The most important thing you need to do for your beardie is #1) Make sure that both your
UVB light and your basking bulb are adequate and set up in the appropriate way, with his basking spot within the correct distance from the
UVB light based on which light you have, and then after doing this, #2) get all 3 temperature zones within the correct ranges.
Bearded dragons have very specific lighting and temperature requirements because they are desert reptiles, and unfortunately there are very few UVB lights that are adequate strength and wavelength for beardies, even if they are labeled as such. So we can help you get a correct UVB tube and get it set up correctly. The only other light you need is a bright white basking bulb that is the appropriate wattage for the size of your enclosure. You should never use any colored bulbs at all, beardies see in full color, and colored bulbs cause a host of serious issues, so never ever use any bulbs that are red, blue, yellow, green, black, etc. You're also trying to replicate natural sunlight over top of his basking spot, and you accomplish this by putting an adequate UVB tube right alongside a bright white basking bulb of appropriate wattage to get the temps correct, both right next to each other and directly over top of his basking spot so he gets both while he basks. Both his UVB tube and his bright white basking bulb need to be on every single day for at least 13-14 hours per day, no exceptions. Too short a photoperiod will result in lethargy, loss of appetite, bone density issues, etc., as will an inappropriate
UVB light, inappropriate or colored basking bulb, and inadequate temperature zones.
GET RID OF THE CALCIUM SAND RIGHT NOW!!! IT IS LETHAL TO BEARDED DRAGONS, AS IT IS MADE SO THAT IT TASTES GOOD AND SMELLS GOOD TO THEM, SO THEY WILL PURPOSELY LICK IT, AND ONCE IT GETS WET IT TURNS INTO LITERALLY CEMENT ROCKS!!! ONCE IT HARDENS INSIDE THEIR GASTROINTESTINAL TRACTS IT WILL CAUSE A HORRIBLE IMPACTION THAT PUTS PRESSURE ON THEIR SPINAL COLUMN AND CAUSES PARALYSIS OF THEIR BACK LEGS!!!! DUMP IN ALL OUT NOW, AND NEVER USE ANY LOOSE SUBSTRATES!!!
Bearded dragons are safest and healthiest on totally SOLID substrates, such as textured slate tile, non-adhesive shelf liner, reptile carpeting, newpaper, paper towels, etc. For right now please get that calcium sand out of there, completely disinfect his entire enclosure and everything in it, as that sand harbors tons of bacteria and fungi, and then put down clean paper towels, replacing them as they get soiled. You can worry about getting a permanent solid substrate like tile later...just as an FYI, bearded dragons are from the Australian desert only, which has no sand at all. It's a very solid, rocky terrain with vegetation throughout, no sand, gravel, etc.