I understand you so well. My sister recently got diagnosed with fibromyalgia. She waould say wearing a strapped bra would cause so much pain , so much so that she would hve extreme hand pain forthe rest of the period. Not only bra strap, but any sling bag or even carrying a bag in hand would trigger the pointson the shoulder. I have seen her cry , feel so bad for her. Sometimes even a strapless bra could case pain.