hello and welcome to HCM forum,
painful swollen gums
can be due to a number reasons,
bacterial or viral infection,vitamin deficiency
,hormonal imbalance , are some of them.
in order to rule out the complete diagnosis you will to get your mouth checked clinically by a dentist
according to the symptoms presented by you, it seems to be an acute infection.
, anti-inflammatory and antiseptic mouth gargle will treat this condition,
kindly avoid hot and spicy food for a while.
i wish you good health.