Thanks for posting your query.
As there is foul smelling discharge from mouth,you have to get a thorough clinical evaluation by a dentist
If there is abscess formed due to dental caries or periodontal infection
,it has to be drained and curetted.
Full mouth scaling has to be done.
If pericoronitis due to impacted wisdom tooth
is developed,get the wisdom tooth extracted or flap overlying tooth has to be removed.
Also get your nose examined by an ENT specialist
Take complete course of antibiotics too.Maintain oral hygiene well.