Concern) When it gets hot... the stress of sun allergy...

I'm not sure since when, but I developed a sunlight allergy. Suddenly, I felt a tingling sensation on the back of my neck, and a rash like hives appeared. If it only stopped there, it wouldn't be a problem, but when I get nervous or tense, that area becomes hot and a burning pain like needles stabbing me occurs. It's very difficult. Last summer, it appeared on the back of my hands, and I had trouble sleeping almost every night. I don't know why my constitution suddenly changed, but as someone who loves outdoor activities, it's really distressing. Now, wearing a neck cover, arm sleeves, and applying sunscreen has become essential. I guess only proper management can save me, right? ㅠㅠ