Both sides of my lingual frenulum and below under my tongue, it is very red, swollen and intermittently painful. started 3 days ago out of no where, with no improvement yet. its like an oval on each side. can it just be irritation, dry mouth, etc?

Possibly just irritation, but more likely related to infection or oral problem. See your regular Dr for initial evaluation. You may need a specialist. Would worry about infection, STD, salivary gland obstruction and other causes.

Possible food burn, irritation, canker sore and trauma to area. If this continues than see your dentist or an oral surgeon.