If you get 10,000 attempts on port 22, you're probably connected to the internet. If you get 10,000 attempts on port 63290, someone has taken a specific interest in you.
Personally? I'd decide the utility of having it public-facing is no longer worth the risk, and firewall it down to a much narrower set of source networks. I'd probably take a moment to brush up on my key hygiene too.