Infant Having High Fever. Took Paracetamol. How Long Will It Take For The Fever To Subside?

Question: Hi, this is Dr. XXXXXXX and my kid is now 9months old. He has been having fever since the last five days. Initially his fever was just mild and intermittent for the first two days. Then from the third day onwards, he started having high temperature but continued to be intermittent. From the day 5, fever started to be continuous and high and is not subsiding with the paracetamol drops and so, I kept a diclofenac rectal suppository. I already consulted my pediatrician on the third day, and he said its just a viral fever and nothing to worry. But Im worried cos, suddenly the fever started to be high and continuous, and also, we have planned to fly to The Netherlands this april 15th which is just five days away from now. Im worried if he ll get well before the flight or is it good if we postpone the plan for another one wk. Also, I wanna know the cause for his high fever. no other symptoms other the fever itself. He is taking my feeds well and is playing inspite of temperatures. Even though all these are reassuring, Im worried, cos this is the first time since his birth he is having a fever ever..pls help me..