Do I hear more than a crumb of FRUSTRATION in your postings? As IN you aren't getting anywhere as fast as you feel you need it? Keep at it! Keep slogging on...
As I've said many times, and will say again, more times...things aren't always what they seem.....it's just a matter of either putting the pieces together in the right order/sequence or batting yer head against the wall enuf times... Tests that show 'negative' results may show a series of 'borderline' results that SHOULD lead appropriately to MORE tests and test results? Goodness knows I went thru a mind-blowing, series of esoteric series of testings before I was diagnosed. IF I had not had two neuros who really, understood nerves and nerve pain, well...Honestly, I would not be here now? I truly was lucky in the 'doc' lottery, I am having heaps of faith that you will find them as well.
IF you read about Lymes' folks, you will know that what they HAVE is a REAL medical issue. Diagnosing it all is full of 'FALSE' Negatives and Positives...We are HUMANS we compensate, at times to our own diagnostic detriments.
I say this, as by the time I 'got' diagnosed? I really, truly felt at the end of my 'mental' ability to 'compensate' rope! Once the diagnosis came 'thru'...it was easy..merely a matter of what TO DO?

PM me please or post here questions about the 'risks of IVIG'...There are some, but IF you are INFORMED, it's an easy route...cost, coverages [insurance], access are a whole other kettle of fish. Yes it can be considered an 'invasive' procedure? But, compared to many, it's a nothing/no-brainer. There are others here who have benefitted from IVIG, not only Melody's Alan. It is a serious therapy, but compared to say, cancer therapies/ treatments it's a far, far less invasive and with far fewwer consequences. Hey, we go on with the getting on?

BTW I do not DO nor tolerate, nor accommodate well any SSRI's myself, some of the other SRI 'clones' don't do well w/ME either...Unless you like a quarter 'human' zombie? Re-visit the Stickies and re-review the whole MENU of optional meds used for Neuropathies...there HAS to be something in that list that could work for you? For me, It's the Keppra, for others not...My spanner in the works has been my cancer post-therapy med, an AI [estrogen blocker]...That can/has turned me into a screaming meemie at times...

Hang in there - something good for YOU IS OUT THERE! - j