Tinnitus with post nasal drip could be due to sinus infections or ear infections, which are a result of untreated post nasal
drip. If you are experiencing these symptoms
only when you are at home, then there should be some thing you are allergic to causing these symptoms. As, you mentioned you are allergic to dust mites, they cannot survive in a humidity less than 50% in the environment, but their fecal matter can be the culprit causing these allergies in your case.