Hello Ed,
So sorry to hear about the troubles here with your calendar loading!
The good news is that the event data is not stored by our plugins at all, but in your website’s database. So, you can download a fresh copy of both The Events Calendar and Events Calendar PRO by logging in here to this site and then follow these instructions to re-install them.
Uninstalling and re-installing our plugins will not cause you to lose data. If any data is lost, then I would most definitely recommend reaching out to your host to see if any other website data was compromised, possibly due to the attacks.
Thanks!
Geoff