Hi there. I'm currently experiencing what you are. I've been so frustrated as don't know how to explain the feeling, but I think you've nailed it.
I was off sick for about 8 weeks and went back at the start of August, but my symptoms have been constant this week so think i'm heading for more time off.
I saw physio last Thursday who gave me vestibular training exercises, but advised not to do them on my bad days as it would make it worse.
The constant brain spinning inside my head keeps happening when i'm in a shopping centre, so I dont know whether it's the bright lights or crowds that do it or a combination of both.
I've also had the tinnitus in my ears and the feeling like they are blocked too and I've had that bad before. My neurologist put me back on a restricted diet of no dairy, eggs, caffeine, chocolate, citrus fruit, chinese food and processed meat. I was also taken off of prochlorperazine and am now only on Nortriptyline (9 tablets daily) now. I don't know where to go from here appart from get my eyes tested to make sure it's not visual