Personally I'd leave it to run its course unless the symptoms worsen. I try to avoid antibiotics where possible.
I'm prone to tonsillitis. I have found that gargling with salt water seems to help.
Take the maximum dose of paracetamol, and ibuprofen if you're able to, even if you don't feel you need it. I saw an ENT doctor a while back (I'm on chemo so infections mean an A&E trip) who told me that the pain itself can make tonsil infections worse, so it's important to take painkillers.