Dog with inhallent allergies?

I have posted alot of questions about my adopted dog and her food allergies. I am starting to think it isn’t food allegies and is something more of inhallent allergies. Her itching is the worse first thing in the morning and I think it is because she sleeps in my boyfriends “messy” room. She also goes and lays in his bathroom. Then when we wake up, Casey and I go back to my house. Although she still itches throughout the day, I feel like it is worse in the morning after waking up. What laundry detergent brand should I use on his sheets since she jumps in bed with us. Also, how do you get ride of dust mites and all that other stuff they might be allergic to? I am Just trying to figure this out. Allergy testing is so expensive and I really do not think it is the food. She has been on Taste of the wild Salmon and Potatoe grain free food for 2 months with no improvement. Please give any and all advise……Thanks- my itchey doodle appreciates it!