I would suggest that you have him seen by a vet experienced in treating reptiles as soon as possible. Being in a position where his head is constantly raised, so that he looks like he is staring up at his lights, is called "stargazing", and its actually one of the first symptoms that you'll notice when a beardie has contracted an Upper Respiratory Infection.
Sitting or laying in that position, with their heads held straight up like, that helps their sinuses to drain and helps them breathe more easily when they're all congested. I would try to get him an appointment as soon as possible, so that he can be given an oral antibiotic to knock out the infection. If the infection is left unchecked, he may develop pneumonia, which could be life threatening.
Until you can get him seen by a vet, be sure to keep him warm, especially during the overnight hours. Raising the temps in his tank at night to around 80 degrees should be sufficient. You can do this by using either a Ceramic Heat Emitter, which screws into his lighting fixture where the light bulb would normally go, or by purchasing a black light bulb at your local pet shop. Don't let them talk you into purchasing the red or blue night light bulbs, as they will disrupt his sleep patterns, and right now he need all the rest he can get.
Also, be sure to keep him well
hydrated, which will help to thin out the congestion in his respiratory tract. The easiest way to do this is to
bathe him a couple of times a day in very warm (not hot) water, making sure that his vent area is down in the water. Beardies have the ability to absorb water through their vents, so this is an excellent way to keep him well
hydrated without stressing him out by forcing fluids into him. Make sure to dry him well before putting him back in his tank, so he doesn't get chilled.
You can also try giving him some sort of juice that he likes with a feeding syringe, if he'll take it for you, but if he won't, then don't force him, as it may cause him to choke. If you can get some juice into him, the Vitamin C in it may help to bolster his immune system and help him to fight the infection. Any sort of low sugar juice is fine, as long as it isn't from any type of Citrus Fruit. I usually use Apple juice for mine, which they all seem to like.
An Upper Respiratory Infection, left unchecked, can be dangerous, but most beardies respond very well to the antibiotics given to them, and recover fairly quickly, with the proper care.
Good luck, and please keep us posted on how he's doing!