My new bearded dragon out of viv is he scared?

i got a new bearded dragon last week, and he is about 6months old i think, he might be under weight because the last owner said he hardly eats but he had been feeding him large cricket. i switched to small ones and he ate a few the first day i brought him home. the next day i put about 6 in hes viv and i just thought hed ate them but i cleaned the viv and they all hopped out of the cave! ive bought a seperate tank to feed im in, but he doesnt seem to like it. and wont eat any crickets, or hes veg. i fed him a meal worm with tweezers he ate that but wouldnt when i just put it infront of him or in hes dish. hes very sleepy and i bathed him today and after that he seemed to become more alert, he has been clawing at the front glass of viv all day, so i got him out he puffed hes beard out when i put him back in. tonight is the second time ive let him loose in the living room, he had a little crawl around but then flattend himself right down in a corner. i put him back in the viv and he went straight into hiding with a puffed out beard. same as he did last time. he will come out of hiding tho in about half hour and sit on the log and then i will stroke him and he will fall asleep for the night