What to do for skin product allergic reaction

Ma

Hey guys, I got The Ordinary brand for my birthday. I used it last week and had an allergic reaction. I have hives and was super itchy all over my neck. I never had an allergic reaction to anything until now. I took some benadryl hoping it would stop the itching but didn’t work. It’s been a week and I still have hives so if you know any medications or products that will help, please let me know!