There are known antiviral drugs which can be given following specific blood tests that will identify the likely virus as well as allowing a diagnosis. Injecting steroids into the eardrum is not a treatment I am conversant with. All of which worries me about your consultations. Might be worth asking for a second opinion from an otologist ie someone who specialises in hearing and the ear. If you are in Spain this should not be difficult. I hope you have also had an MRI to exclude an acoustic neuroma. However I do accept the vast majority of cases have no demonstrable diagnosis and in that case it is a question of hearing aids, although I struggle to understand why your AME might require an annual review as further consultations at that time would have no benefit beyond an audiogram.