I'm sorry you're dealing with this, it's not your fault, but you're not going to be in the clear until you get him a proper
UVB light and fixture, without one for as long as he's not had one he's probably feeling very badly. And you also have never dusted his food or veggies with Calcium? Without a
UVB light and zero Calcium, he's probably very sick feeling, lethargic and very weak/tired, and his bone density is lessening every day. A full hour outside each day in direct sunlight is enough to help him, but he needs his insects dusted in Calcium WITH VITAMIN D3 every day, because without a
UVB light he's not been making his own vitamin D3...
Assuming you can get to a Walmart, they sell a big bag of proper greens for beardies with the rest of the fresh vegetables that you put in little bags yourself. Look by the lettuces and you'll see some different pre-packaged big bags of greens, and there is one called "Greens Trio" that has only collard greens, mustard greens, and turnip greens in it, all 3 are excellent for beardies. It's a really big bag (make sure you wash them well before feeding them and keep them in the refrigerator). The entire bag costs $2.98, and you get quite a bit. I suggest keeping the greens in the crisper drawer in the bottom of the refrigerator.
Also at Walmart, back in the Pet section, in the aisle that has fish food and aquarium stuff, near the bottom shelf under the fish food they sell some crappy freeze-dried insects in bottles (never feed your beardie insects that aren't alive), but next to the crappy freeze-dried insects they sell little jars of Flukers brand Reptile Calcium powder With Vitamin D3, and a jar of it only costs like $3.98, cheaper than pet stores by far. You need to get him this and dust all of his live insects in it, and sprinkle it on his veggies too. Then be sure to get him outside in a plastic tub for at least an hour of direct sunlight each day. This is the best you can do until you can get a proper
UVB light and a fixture for it. So if you can come up with $7-$8 you can get a big bag of excellent greens for him and the very important Calcium powder.
Out of curiosity, what state do you live in? I have some ideas/connections I might be able to help with...