Hello, Christine32, Welcome to the forum.
I have tacyile allodynia on my entire back. Neck to below hips and side to side, stopping under my arms. I've had it for almost a year. I take gabapentin, which I know isn't suitable for everyone, but it helps me. It doesn't completely eliminate the pain,, but it does make it a bit more tolerable.
As to clothing, I find more snugly fitting jeans work better for me, as they don't rub like looser fitting ones do. I wear my Jockey cotton underwear inside out, so the seams don't rub, and Wacoal (and other brands, I'm sure) make seamless underwear. Many years ago, before this started, I splurged and bought 2 silk camis from Nordstrom. I brought them out of storage, and they are a godsend. I dread the time coming when they wear out. Unfortunately, Nordi's doesn't make this quality of product anymore, but they do have silk camis that might work for you. I think they are $68 each. If that's out of your price range, I'd bet that a nice poly or cotton/poly blend might be soft enough.
I hope you find some help, here and from other responders. Good luck to you.