Please prioritize treating your cavity before attempting to whiten your teeth. Whitening products contain active bleaching agents (like hydrogen peroxide) that can penetrate the cavity, reaching the inner nerves and causing severe pain or permanent tooth damage. First, visit a dentist to have the cavity filled and restored. Once your teeth are healthy, you can safely discuss whitening. Your dentist can provide professional whitening or recommend safe, dentist-approved at-home kits. Avoid over-the-counter whitening strips, abrasive charcoal toothpastes, or DIY kits until your cavity is fully treated, as they will worsen sensitivity and damage weakened enamel.