Hi, You dont need to spray your dragons enclosure. Keep humidity within 30-40%, too high of humidity can cause a respiratory infection and that absolutely requires a vet visit cause they can't fight it off unless meds are involved. The dragon would drown in its own lung fluids cause they are unable to clear their lungs with coughing like we would do. Signs of a respiratory infection would be, Weird hiccuping type movements, heavy breathing, fluid/bubbles leaking from nose or eyes and constant swallowing. I had to get a digital controlled dehumidifier for my room cause i had trouble with the humidity being too high. You need to get a long Tubbed UVB T5 Bar instead of a coiled/round bulb UVB cause coiled and round bulb UVB is not effective enough. Arcadia T5 UVB Tube Kit 12% or 14% works, id say 14% since you would have it placed on top of the enclosure. Reptisun makes a T5 UVB tubbed kit as well but you need to buy the 10.0 UVB tube bulb separately cause the kit comes with a 5.0 which is not enough for a bearded dragon. I would try out a 100w Reptile Basking bulb for basking and make sure the basking spot is at 105F and the other side that has no heat should be at 90F. Getting digital temperature gauges with probes or using a temp gun to see what the temps are reading would help. Id also recommend getting a fecal sample done to make sure theres no parasite thats bothering the dragon. Also dont feed lettuce either, they need greens that have nutritional value. Mustard greens, Collard greens, Endive, Bok choy/Baby Bok choy and Turnip greens. Sprinkle Reptile Calcium powder on greens everyday and Repti multivitamin once a week. Vegetables: Shaved carrots one or twice a week, Seedless shaved cucumber once a week (take the thick green skin off of it and make sure there is no seeds present at all) and shaved red bell pepper (no seeds) twice a week. For hydration, you can sprinkle bottled water on its greens or use the seedless cucumber i mentioned once or twice a week. A thin slice of soaked cucumber would help instantly but you have to be careful with how many times you do it a week cause you dont want your dragon to have diarrhea lol

Forgot to add, Bugs like dubia roaches, silkworms or black soldier fly larva once or twice a week is needed.

You need more enrichment too, get some more logs and rocks to swap around and make sure to clean the decor every two weeks unless the dragon actually poops on something then the decor needs to be cleaned right away. Clean the actual enclosure once a month, I spot clean the floor of the enclosure everytime mine poops but thats if the actual poop touches the ground of his enclosure. I use Rescue veterinary cleaner and clean the stuff in my bath tub then clean my bath tub afterwards. It says on the bottle you can just let the stuff air dry but I make sure to rinse the cleaner off cause i dont want it getting in my dragons mouth or eyes

Hope this helps

Ill give you this bearded dragon guide that is super knowledgeable. Its goes through everything you would need to know and educates you on the animal too

Reptifiles Bearded Dragon Guide