Too slow at running 5K after C25K

I've been doing the Couch to 5K program for a while now, and I'm currently at the last week of it. I can now run for 30 minutes straight, but way less than 5K in that time. The issue is that if I were to run 5K, I would only be able to run it a lot slower than 40, let alone 30 minutes, at my current pace... which, according to a quick Google search, is a much worse time than the average novice runner at my age and sex.

So what now? I'm kind of clueless about what to do after this program, because now that I can run for 30 minutes, I want to actually run 5K in those 30 minutes, like the program implies.

Thank you so much for the responses in advance.