according to Google, cat purrs are at a specific frequency that somehow helps you heal faster

One of it's purrrposes is to shake wounds and increase bloodflow. This is why cats sometimes pur after conflict; they're licking their wounds in multiple ways.

afaik the notable thing is actually that the purrs help heal bone fractures, which is presumably something to do with vibrations helping the process along mechanically somehow.

But of course there's also just the psychological effect of having a purring cat near you, same thing as how people heal faster from stuff like acupuncture despite the process itself not doing anything, we just benefit from feeling happy and cared for.