One thing with fibromyalgia is that when something says that clothing is the most comfortable thing in the world; it probably isn’t. There will be a weird seam or the elastic will be too tight or the fabric just seems to burn on my skin.
I saw Carole Hochman pajamas at Soma and then went to ebay so they would actually be affordable. I’ve heard that they are available at Costco too. The ones I bought are modal and are the most comfortable thing I own. I don’t know how long they will last but the elastic isn’t super tight and it’s somewhat soothing on my skin. Go and get comfy you deserve it.