I feel the filling which you did yourself may have covered an infectious area. a filling can fill the gap but can not remove infection, which has to be drilled out by the dentist
. I do not think that the conjuncctivitis is related to your dental problem but you surely have infection in your body which needs to be treated with antibiotics and pain killers.
For sore throat
you can start with warm saline gargles.
i would strongly recommend you to visit your dentist for the aforementioned tooth.