Hi @albeit
I did a very quick search for relationship between SFN and tinnitus. The only thing I found was tinnitus and SFN as a result of chemotherapy.
I also have tinnitus, but it preceded the SFN.
Tinnitus is usually caused by hearing loss. The brain manufactures sounds, because of the lack of input. That's why when people get hearing aids, the tinnitus is often reduced.
I'm pretty sure my hearing loss/tinnitus is caused by too much loud rock'n roll back in the day.
Also, by definition, PN is a disease of the peripheral nervous system. Problems with hearing, chattering teeth, and foggy thinking all would involve the central nervous system, so I think PN is an unlikely cause. However, as we all know, this is a strange disease, so I wouldn't bet on that.
Don't try to come up with your own diagnosis. Just tell the neurologist all your important symptoms, but try not to overwhelm him/her with every or short lived symptoms you can think of.
The frustration you feel is understandable. It would be helpful if you understood that the medical providers are also frustrated, and often can't come up with an answer to everything. As an example, my SFN is idiopathic, which means unknown cause. I know how it feels.
Jeff