Sick Leave!

Cassie • 20 years young • Australia • Taking it as it comes
I'm a casual waitress and tomorrow morning I have work from 10-3. It's currently 12:12am and the left side of my face is swollen due to what I believe is an abscess, my ear is even aching I'm at a point I want to cry and I feel nauseous. I've taken the maximum amount of painkillers and numerous home remedies but nothing has helped. I know I'll need to go to the dentist tomorrow but my boss is known for not being the nicest person. She once abused a girl I work with for not being able to work - she had a doctors certificate and everything. The girl was reduced to tears and I'm absolutely petrified she's going to abuse me for it as well. I don't know whether to attempt to go to work tomorrow or call in sick and get a certificate and hope for the best. In my situation where you had cause to miss work, would you still consider it worth the risk?