I LOVE my white pine outfitters martingales. I've had them for years and years. so nice, soft and colors do not run. Those are my "go to" walking collar/leash.
Bummer that the thundershirt did not work. I just got one (about a month ago) for Zest! and our Q rate in agility has, literally, spiked.
I doubt the Dog's Ear book will help, but it's sort of interesting reading and has a cute basenji on the cover. you could always check your local library, that's where i think i first found it. again, maybe a piece of the puzzle.
I know Zest! did go throught a period where she hated her crate, but not to the extreme you've described. And of course once she slept in our bed, she never looked back. (that was not planned, but due to a late spring snow storm that killed power for 24+ hours. I did not think her freezing in her crate was going to help her like the crate.) And I do have other dogs, so she was never really "alone". We did do crate games. We did more of Overall's RP. (And boy were those conformation people impressed with me sending her to her mat! easily amused, those people)
Oh, and congratulations - your learning curve is about to seriously increase! (I know that may or may not make you feel better now, but someday . . . )