What is wrong with my lizard?
it sounds as if your beardy has calcium problems, if you use a strip light u.v lower it down to the floor, working in a reptile shop i encounter this problem often. despite what the packaging of the u.v says, once the u.v is more than 6 inches from the lizard, its effect starts to diminish and past 12 inches the lizard gets no u.v benefits. this is especially true if a reflector is not used, so if your u.v is on the ceiling lower it, ive never had any problems with the lizards burning themselves as the strip lights dint get hot enough. the retching you mention is a common sign of respiratory problems, is your viv warm enough. iwould take him to a vet but do try to find a specialist reptile vet as normal vets dont allways know what to look for, good luck!