PLEASE HELP BEARDED DRAGON WONT EAT. WHY?

He's sick, there's something wrong with him, you should take him to the vet. And while youre at it, if you are able to, you need to contact the previous owner about any problems he may have had, you need to be careful though, if you did not personally know the person, and you paid money for him, she's not gonna tell you about any problems he may have had, bearded dragons are expensive, and sometimes when they get sick, they will sell off the dragon not letting you know whats going on, so that way they can get a new one and youre stuck with a dead one and out of however much you paid. You really need to take him to the vet though, you should have taken him when he was draging his back legs