Welcome to WHL. Your symptoms are a bit of a mystery. I'm not sure what exactly is going on with you. When you mention the blood work being normal, did this include an ANA test? Ibuprofen and NSAIDS like Aleve (Naproxen Sodium) are indeed linked to phototoxicity in some individuals, so the sudden sunburn rather than tanning makes sense. The best thing I think you can do is to keep up with the follow-up appointments with the Rheumo, and possibly seek a second opinion as well. What is often times unclear to one specialist, is quite clear to another. Someone with a fresh perspective could help you find an answer sooner than later.
I know what you mean about not only wanting, but needing to get out and enjoy life. Be it your camper, or my sailboat and kayak, it's a fun family activity that quickly becomes tradition, and you hate to miss out on it. I don't know where you live, but here in Maine, summers can be short, so I try to get out at every opportunity. If you are having sun sensitivity problems, you can still enjoy an active outdoor lifestyle. You will need to learn some "shade discipline", as I call it. I have my wide brimmed boonie hat, spf50 waterproof sun block, and a lightweight and light colored long sleeve shirt with me at all times. I also stick to any and all shade I come across during my daily outdoor activities. I have both SLE, and MS, and the sun can cause me to have a Lupus flare, and the MS is aggravated by heat, but I'm able to navigate my little corner of the North Atlantic despite it. I get alot of joint pain as well, and I just have to go easy on the bad days, and push myself on the good ones.