If you are really worried take him back and see a different doctor for a 2nd opinion? I remember when Ty was sick for the first time (around 5-6 months) and I just felt soooo scared

Talking to the doctors always reassured me. Sometimes it can help to talk to the nurses at HealthLine (0800 611 116)
But I totally agree with mamanee about the pamol, cuddles and fluids! Just give him lots of small drinks of water, and keep an eye on his temp. Cuddles from mum are the best

He will be totally miserable... especially because it's the first time he's been sick he's probably wondering what on earth is going on
Hope he gets better really soon!