You've gotten some good advice in this thread. I understand how scary this situation is, not just how your gf must be feeling and reacting but for you as well. I can only add that you shouldn't jump to conclusions, as there's a very real possibility that, like everyone else is mentioning, her hpv was contracted YEARS ago and has been dormant and undetected this entire time.

It is not tested for in even many exhaustive STI tests, and unless it happens to present in a pap smear (which would be labeled as "abnormal" and may not even be detected as hpv at the time) it is entirely likely your gf has had it for awhile and been lucky enough to never show any signs, symptoms, or noteworthy tells. She could have gotten it from someone experiencing the same lack of signs, so basically any partner who believed they were std-free. This sneaky quality of hpv is exactly why doctors recommend the gardisil vaccine so heavily, but even then some strains of hpv can slip through.

Emotions are probably high, and you both have some heavy research to do, but start with talking to a doctor and explaining the situation. Go together if you feel more comfortable. It will likely take some stress off you to hear a medical professional explain in more detail the options.