I can't believe the doctors you've seen!
You've gone to your regular doctor with a boatload of pretty serious symtptoms and he told you it wasn't an inner ear infection. Well, OK, that rules out ONE possibility, but what other tests were done? Please don't tell me he just sent you home! The sudden weight loss, which is a significant amount and should have raised some red flags was apparently simply ignored? Fainting and sudden weight loss are seldom. IF EVER, symptoms of an inner ear infection. Go find another doctor who actually went to medical school. The ER was on the right track to do an MRI, but when that came back clear, what? They ALSO just sent you home?
Where do you live for crying out loud?
You absolutely need to get a second...........well, I guess it would be a third opinion by now. But you absolutely must find someone who will look at the entire picture and start doing appropriate testing to rule various problems in or out.
If you live in a small town, please get someone to drive you to the nearest large city and seek help there. You can call ahead to a hospital, tell them whats going on, they will refer you to the type of doctor you need to see.
I wish you the best and hope you will let me know how you're doing.
I know a bump on the head, as in your past, can cause the inner ear crystals
to move out of place: Nause, room spinning feelings, vomiting and fainting.
I had severe fainting feeling that lasted seconds intermittently over a few months. Now mainly over that. Saw an ENT(ears, nose and throat specialist). Easy cure for me. Also had the same symptoms as yourself after banging my head(unexpectedly). So I too know how your symptoms can be severe. Mine was a positional dizziness. So this situation was one cause. There are others that the specialist should be able to diagnose. Hope this helps. See the ENT and maybe your cure is just around the corner!