Hi Jillyboo!
I haven't been on the forum for a while and missed your post. I also suffer from polymorphic light eruption, aka sun allergy or sun poisoning. I was diagnosed in my 20s. I wear sunscreen everyday and stay covered up. I have a hat collection. I have to be careful in the early spring as the light intensifies. I'm very good at avoiding flareups and haven't had one in 25+ years. I may get some itching on sun-exposed areas in the early spring, usually on my hands because I've forgotten to reapply sunscreen after washing. Some people only get the skin reaction, I also get the nausea and feel terribly unwell.
I tend to acclimatize as the summer wears on, but I dread spring and always look forward to the end of summer.