I sympathise with your situation, as I was in same position as yourself after four months of sick leave. I too had all the tests MRI, balance and waited weeks for diagnosis, which was incidentally inconclusive, I have most of the symptoms ie hearing loss, vertigo, tinnitus, ear fullness of Menieres, but am still without a diagnosis. Was discharged until I have any major symptoms again. Was frustrated and confused as audiologist who did balance test confirmed hydrops. Please read my previous posts for info.
I returned back to work before my final consultation on a phased returned four hours first day, one day per week and gradually built it up to be full time again, struggled in noisy office but found it good to be back in the normal world. Hope it gets easier for you, just know your limitations and try and keep relaxed. I have been back at work now six months and I still have problems occasionally but try to remain calm and positive. Have eliminated caffeine from my life and follow low salt diet and this has greatly helped my tinnitus.
Hope you get a firm diagnosis soon. Take care Alison