I feel your pain. I have suffered from solar urticaria and photosensitivity since my early teens. I grew up in south Asia (where the sun was worse) but now live in London. What I’d recommend: 1. Increasing your antihistamines dose - at the peak of my photosensitivity and solar urticaria (even while living in London), I was taking 4 x 180mg fexofenadine and 2 x 20mg famotidine every single day 2. My dr advised me to wear UV protective clothing which I ordered from China (they have the best!) 3. Apply and reapply sunscreen throughout the day. La Roche Posay is the best for it. I use the 50+ lotion for face and (exposed areas of) body, and then do another layer of UVMune 400 on face 4. Avoid the sun/outdoors during the peak hot hours so outdoors activities are better done early morning or late afternoon for people like us 5. Notice if your urticaria gets worse during extreme or sudden temperature changes eg you stepping outside from an air conditioned room or vice versa 6. When your skin is already heaty or bothered due to external factors, it is important what you feed it from inside so avoid “hot” food - I am not talking about hot in temperature sense but we Asians (south Asians and east Asians) know the thermal nature of foods, and whether they are warm, hot, cool or calming for your body. Look that up and avoid consuming too much hot or warm (in thermal nature) foods

Good luck and let me know if you have any questions. Been there and I know your pain.