Unfortunately that is all you can do at the minute. Has h started the meds? If not, I'd start them now. I'm surprised your Gp wanted you to wait, tonsillitis is something to action straight away as it doesn't resolve itself.

The meds should kick in pretty quickly but it may take a couple of doses to see big improvement. Try to keep his fluids up any way you can. Ice cream, jelly, custard all count as fluids. And keep up regular panadol and neurofen for pain.

If he breaks 40 or becomes lethargic or hallucinates, I would recommend a trip to ED where they can assess if he needs IV antis or IV fluids.

Hang in there.