Temperature in 6 month old

So my little boy started getting a temperature yesterday along with faster breathing and a new high pitch cry, I phoned his doctor and he recommended starting some antibiotics to be on the safe side with everything going on at the moment.

However since I’ve spoken to his doctor his temperature is spiking more, I’ve given calpol and ibuprofen to lower it and the lowest I’ve gotten it it 38.5, but it fluctuates between that and 39.2. But now he’s also stopped drinking his bottles and shivering, im so worried to take him to the hospital incase we pick up something worse (we are a high risk for corona).

Any advice? Should I call the doctor back?