Although younger BDs eat a much higher percentage of live food, he should be getting at least some greens now, then more and more as he gets older.
You can put some finely chopped kale, collards or mustard greens in a shallow bowl, then drop a few small dubia or crickets in. Try to keep it 'fluffy' so they get under it and so it's easy for the BD to pick up. The dubia/crix will create motion and he will either grab the greens reflexively, or get them accidentally with a bug.
You should be dusting his live food items with a calcium/vitamin D supplement, and these supplements seem to taste fine to the lizard, so sprinkling a little dust on some of the greens may help fool him into eating them.
For those slow to catch on, I'll put a little water in a shallow dish, then put the cut up greens in/on the water and just leave them in there for a few hours at a time. The water helps keep the veggies from wilting and very often curiosity/boredom will drive them to try some.
Different greens have different flavors. My lizards will eat mustard greens and collards, but prefer kale, so you might try a few different piles to see if he will eat at least one type. Kale is good due to the texture (easy to eat), but not the best food from a nutritional viewpoint. Anyway, they usually get used to eating greens pretty rapidly and most love them.
If he will eat from your fingers, you might try offering very thinly sliced yellow squash, watermelon, apple (no skins/rind) or strawberry as a treat. The sweetness and moisture usually appeal and mine will act very excited when they see me with something colorful.
The general rule of thumb with bearded dragons is that they should not be fed live food items that will not fit between their eyes. This is because their digestive systems cannot handle bulk amounts of 'roughage', especially when young. One might assume their natural food items are smaller, softer bugs, caught far more infrequently than being fed mass amounts in captivity.
In my opinion, he has had too much of the wrong food (most LPSs have NO clue) and we should be thinking 'damage control' at this point. Mealworms and superworms are both a little big for him and when we combine the prey size with the chiton content, he may be unable to fully digest them.
If your guy has eaten 40 superworms in the last week, I'd be VERY concerned about getting that load of undigestible chiton (the worm's exoskeleton) through him. Introducing moisture and some vegetable matter will help. I'd continue soaks in warm water as a stool softener and try to get him to eat something moist to work on it from the other end. Mine will eat some baby foods, and you might try some various fruit/vegetable types to see if he'll take moisture that way. Squash, peas or spinach might appeal to him. Another thing that can help is to provide a very small amount of olive oil. It seems tasty and many lizards will lick it off a dropper, or it can be applied to greens if you can get him to eat some.
If your lizard begins to show signs of difficulty using his back legs, many times as bad as almost total paralysis, it is almost certain he is impacted. If this happens, a trip to the vet is probably the only thing that can save him
As far as brumation, it is unlikely that this would happen at 4-5 months. Far more likely is that he is just laying up with a full belly, trying to digest what he has. Keep him warm to aid digestion, if he stays cool at this point, it will delay digestion and may make matters worse.
There is a huge amount of care information over at
BeardedDragon.Org that you may find helpful. They even have a 'Beardie ER' forum where immediate problems are often solved.