Calender suddenly reset - all events and calender categories are gone

I use my calendar frequently and have created new "calendar categories" in fun colours apart from the ones that come with the app. I just opened the app (for maybe the 10th time today), and all my events, both old and upcoming are completely gone, including the new categories I had created and used for all my events. The only categories left are those that come with the email accounts, such as birthdays, and the few events that I created in those categories are still there.

The settings have completely reset too, as reminders from the Reminders app now show up in my calendar - a setting I turned off more than a year ago. Has anyone experienced the same thing, and how (if so) did you fix it?? I do not have my calender synchronised on iCloud (as far as I know), at least nothing is showing up in my calendar on my Macbook either.

The first thing I tried was to free up some space and restart my phone, since it gets a bit buggy when it doesn't have enough space, but that didn't help. I then tried some of the solutions I found on here, such as choosing a different default calender, toggling all my accounts off and back on, etc. I also tried resetting my calendar with an earlier version that apparently was saved sometime last night, but nothing happened, which is weird since my calendar app was normal up until maybe an hour ago, so the earlier version should have all my events...

Pls help I need my events back, I had sooo much important dates saved up until June of next year... I do NOT have all of those in my head 🙏🙏 🙏