Redness and sensitivity on tongue suggests that the tongue mucosa is inflammed. This can be due to allergy to certain tooth pastes and mouth rinses
, traumatic tooth brushing or tongue cleaning .injury to tongue due to hot food stuffs, Deficiency of certain vitamins also leads to redness and sourness. You can apply antiseptic and analgesic
oral ointment like mucopain topically which provides numbing effect. Multivitamin
supplement like zincovit and vitamin C
lozenges helps in quick healing. drink lot of water to keep yourself hydrated and citrus juice. i hope that helps you , take care.