Past events on iPhone Calendar missing after removing CalDav account

I had my Google calendar account on all my iPhones throughout the years set up with CalDAV. About a week ago, on my iPhone 15 Pro running iOS 18 I started getting the dreaded "Password Incorrect" error message for the account. I removed the account from my phone, and then re-added it using my standard @gmail account login rather than the old CalDAV method.

Any current events that I add sync just fine between my phone, computer, and the Google Calendars webpage. However, all my calendar events I had from before are completely missing everywhere. I tried desyncing and resyncing the calendar account, and checking the deleted events section on the Google Calendar webpage, but there was nothing there. Is there any way I can get those events back? I don't understand how they could have vanished into thin air.