I suggest not using a pillow, or using the thinnest one you can. I used to have upper back/shoulder pain and went to a chiropractor. He showed me that my “hea

I suggest not using a pillow, or using the thinnest one you can. I used to have upper back/shoulder pain and went to a chiropractor. He showed me that my “head carriage” was off - I held my head too far forward, which caused neck/shoulder muscles to strain more to keep the head up. I corrected it by not using a pillow when laying on my back. A decade of pain gone in a couple of nights! YMMV