hello and welcome to HCM,
You seem to be having an infection of the throat which is quite common. Also some pain medications may make you nauseas especially if you take them in an empty stomach.
If you still have difficulty in swallowing then you need to see an ENT who will perform a proper examination of your ear, nose and throat and initiate a definitive treatment.
also avoid taking any cold
drinks or food. Your subnormal temperature may be due to a multitude of causes which can be deduced only by a doctor.
take care and get well soon
Dr Sriram Nathan