Hi, he is a little one for sure. Is this your first bearded dragon? Sorry to hear he isn't eating on his own. When you offer him crickets, how many are you putting in at a time? If the crickets are jumping a lot, he many have trouble grabbing them so you could put 1/2 dozen in a ziploc bag and place them in the frig for a few seconds so that they aren't quite as jumpy. Are you feeding him in his tank?
When you say you have been hand feeding him, does he willingly take a cricket out of your fingers or do you wait for him to open his mouth & then pop it in? Are the crickets smaller than the space between his eyes? Are you dusting the crickets with calcium 5 days a wk and with vitamins the other 2 days a wk?
If he doesn't start eating more than one cricket daily, the next step would be to pick up some chicken or turkey and squash or sweet potato baby food so that he can get some much needed protein and nourishment into him.
Where does he spend most of his time when in his tank? Is he quite active when in there? Has he pooped lately?
Could you fill us in on the size of the tank, the wattage of the basking bulb(s), and the brand & type of UVB?
Also, what type of thermometer are you using, round gauge (dial), digital strip, temperature gun or digital thermometer with a long wire & probe end?
Sorry for all the questions but we need to make sure that everything is perfect for your little one.