I dont understand

Question
Hi i was wanting to ask a question about my bearded dragon, he's only 6 in. and i got him about a month 1/2 ago. He's been doing just fine till recently I have noticed him not eating at all. And his head goes back and forth real fast like he has a spasms. I know that he hasn't eaten in a couple days he used to be fat now he's getting skinny, im really worried about him im terrified that he might die. Me and my mom have been trying to feed him crickets, worms, and salad, but he refuses and starts to fall asleep. Please help.

Answer
 Hi Sarah, I ish I had been able to get online sooner.  I really would have needed to know the set-up you had for him.  If you had gotten him from a pet store, the chances are you were yold to buy all sorts of stuff, and many times the stuff they sell you is wrong, even bad.
 First you must take this baby to a good reptile vet if he is still alive.  He may be impacted from the wrong stuff on the bottom of his tank.  Or he had the wrong lighting or temperatures.  The vet, if he is good will ask all these same questions and he may be able to diagnose and treat the problem if it's not too late,