A lot depends on how long you've had it. If only a few days, try coating it with milk of magnesia to make eating easier and keep food and drink from irritating it. Also, do what SassieLassie suggests, after 7-10 days, if no better see your dentist.
Your descriptions appear to suggest a benign soft tissue neoplasm.If it provokes electric, shooting , or burning pain, traumatic neuroma or benign nerve sheath tumor are likely differential diagnosis. Seeing an oral surgeon is advised.
It could either be a cold sore or a canker sore, both hurt. Try swishing some hot salt water around your tongue for a few minutes, this might help.