Juvenile bearded dragon won’t pick his head up and won’t eat

We got this bearded dragon about a week ago and he was completely fine until yesterday when he started pushing his head into the ground and will only pick it up occasionally. He has stopped eating today even though he was active and ate 5 crickets yesterday. When I try to pick him up he will sometimes do a barrel roll as if his head is too heavy for him. He also won’t stay on his basking rock and instead hides in the cave below it. Does anyone have any ideas of what could be wrong??

Hi. Poor guy. What is the setup like? Temps? How you take them? Lights used? Brands? Size of the enclosure?

Yeah very sorry for your dragon. Though here is a template you probably should answer first before getting into any other detail:

How old is your dragon?
How long have you had your dragon?
How long is your dragon?
What is the sex of your dragon?
What size enclosure do you have your dragon in?
What type substrate do you have on the bottom of your tank?
Do you use UVB lights?
If so, Is it a coil, compact, fluorescent tube, or Mercury Vapor bulb?
What is the brand name and number of your bulb? Wattage (if MVB)?
How old is your UVB bulb?
How close can your dragon get to the UVB?
Do you use a separate basking bulb? What kind and what is the wattage? Is it a white or colored bulb?
What are the basking temps?
What is the cool side temp?
Do you take the temps with a stick on thermometer, a digital thermometer with a wire and a probe end or a temp gun?
Where exactly are you taking your basking temps?
Do you use a heat rock or heat pad?
What do you feed your dragon? Please be specific.
How often do you feed and what time do you feed (morning, afternoon, night)?
Do you gutload (feed) your crickets, worms, etc?
Do you use vitamin or calcium supplements? What brand(s)? How many days a week do you use each of them?
Is your dragon having regular bowel movements (poops)?
Do you bath your dragon? How often?
Do you mist your dragon or offer water other than in the bath?
Have you gotten a vet check and fecal done?
Does your dragon share an enclosure with another dragon?