For HSV-2, here's one study on the rate of transmission for discordant couples. As I recall, the study mentioning the 4% transmission rate was 4 sex acts per week over a year. Given the low transmission rate, odds are that on average contraction came from a single incident implying 4/(452100)=4/20k or 2/10k.

HPV transmits via similar mechanisms so one would expect a similar transmission rate. The biggest HPV study was described here. In this case, the study period was only 6mo so the numbers aren't quite as good about 1/500. However, only 50% of those reported using condoms and transmission rates are lower female-male. Dr Hook reports the odds at 1/1000 on medhelp, presumably based on anecdotal experience.

They're highly prevalent diseases for a few reasons. First, people have sex often. Second, people have sex many years of their life. Third, there's a lot of people. Put another way, if every American had sex only once and each time it was with an HSV-2 positive person, we'd have 60k new infections, enough to flood the internet with stories but still a trivially small number considering the 300M people we have. To contract, people need to have enough sex to become statistically significant AND have bad lucky at the same time. It can and does happen certainly.

The doctor at the urgent care clinic advised that from a medical standpoint there was no need for me to stop having unprotected sex. I abstained over this period anyway as an extra precaution because I wanted the extra assurance of no symptoms over the likely window period and a round of negative tests. The outstanding issue at this point is where to get the tests done.

Ethics are besides the point here but I've consulted with medical and relationship professionals on the subject already. Needless to say, their advice differs from popular opinion but their responsibility is towards the relationship only, not towards solving social injustices in general. They're not out to make me a poster child in other words.