2-year-old has a vaginal infection and I'm literally sick with worry

We just came back from the dr's office and I had to take five minutes to just breathe because otherwise I was going to throw up. I've been in panic mode since yesterday when she came back from kindergarten, acting normal but with a 39,8°C fever. And discharge in her underwear.

I'm very worried about these kinds of infections. I feel like if you find out about them one minute too late, they develop into lifelong complications and serious problems.

We got prescribed antibiotics, the Dr didn't seem too worried, she just didn't want the infection to spread to the urinary system. She said it's probably caused by toddler hygiene (you know, when they insist on doing everything themselves, even wiping, and it's not always effective).

I'm so stressed about this I feel like I will fall apart. Can someone talk me off the ledge?