Hi Julian! Apologies for the delay in responding here. As a hosted customer you can always reach out to team@discourse.org to get quick, personalized support from our team. We can also look at your site’s stats and settings directly to advise you.
That bump in pageviews does look impressive, and you are indeed over your limit. Don’t worry, though, we won’t start charging you more without talking to you first and helping you to get back under your limits.