Pigmentation on the cheeks is often treated with creams like hydroquinone, but using too much can easily irritate the skin. The redness you are seeing is most likely a reaction to overuse, where the skin has become sensitive and inflamed. You should stop using hydroquinone right away to avoid making it worse. Wash your face gently with a mild cleanser and cool water, and avoid rubbing or scrubbing the area. Keep your skincare very simple for now. Applying a plain moisturiser may help calm the skin and support healing. It is also very important to use sunscreen every day, as sunlight can worsen both redness and pigmentation. Try to avoid other strong skincare products until your skin feels normal again. If the redness or discomfort does not improve within a few days, please consult a dermatologist, who can thoroughly examine your skin and recommend safer treatment options for your pigmentation.