Sun pain or invisible sunburn

I have become intolerant of sunshine. Direct sun causes what feels like a sunburn, but it happens within minutes and it lasts for hours to days depending on how long the exposure was but leaves no redness. It is limited to the area that was exposed and feels exactly like a sunburn does. I'm struggling to find more information on this, and am looking to hear from others that have experienced this or something similiar?

I have made an appointment to follow up with my dr, and am guessing it will result in a referall of some sort. Searching online suggests SFN or fibromyalgia might be the cause. It would be helpful to hear from others who are going through, or have been through this to understand what causes it and if it ever goes away?