There is no "this is it" answer for me, it is more a combination of things. I have been diagnosed with Meneire's disease, a catchall type of disease that is given when everything else is eliminated. It comes with vertigo, dizziness, tinnitus, hearing loss in varying degrees. I also seem to have a genetic link to early hearing loss. They seem to have given me a double whammy, at least that is what my ENT guy thinks.
I have also wondered about the autoimmune thing. I was tested and it came back negative. But, I have chronic iritis (inflammation of the iris) that my eye doctor swears is due to "something hinky" in the immune system. If you were to ask him, yes, it is possible. It could be at a stage where it does not register in the tests. But who knows?
As for coping? It ain't easy... Honestly, I am usually an upbeat person and don't let things get me down for long. I always try to look for the good things. All in all, there are just days that I will cry for no reason (yes, there is, I know that..but..). I call them my "pity parties" and they are needed.
What helps me the most is telling myself that it could be worse. Ok, so I am deaf when I take my ha off and speech sucks when I do have it on. There are others that deal with being deaf every day and have dealt with it for far longer. They don't sit around and mope about it..they get up and live. That is why I joined this forum. To help balance my life and learn. I could be dealing with a life threatening condition, be in constant pain, any number of things.
But, at the same time, for a person that has heard "normally" for half a century, it does suck..which is why I have opted for CI implantation. At this stage of the game, I don't really care if music sounds good anymore. I just want to be able to understand speech again. :Oops: mini pity party snuck in for a sec. I too, sometimes, crawl into a shell. In large crowds, more often than not and I think that is normal too. It lets go of the stress trying to speech read causes when so many people are around.
It all comes with the territory..you just have to learn to make the best of it as you don't really have a choice. As long as you have a support system and someone to talk to, you will do just fine. If a therapist helps, use one. A close friend can do wonders too. I am glad you are becoming more fluent with ASL, that will help too since you are around those that share that language. It all sounds like your life choices have been made for a reason, though you didn't know it at the time.