''This iPhone was lost and erased.'' and activation lock required after IOS 14.0.1 update

I have an iPhone 8 Plus which I bough second hand, online, this summer. When I got it from its former owner, she reset the iPhone and I put in my iCloud account.

Everything worked fine until today, when I updated my iPhone to the new IOS 14.0.1, when I open the phone it reads ''ACTIVATION LOCK>This iPhone was lost and erased. Enter the Apple ID and password that were used to set up this iPhone''. When I put in my iCloud, it doesn't work. It says I can't unlock the iPhone with this iCloud account.

On ''Activation Lock Help'', it reads ''A password is required to activate this device because its owner has used Find My iPhone to link it to their Apple ID. If this is your device, enter the Apple ID and password you used to set up iClous. If you were given this device or purchased it second-had, you will need to contact the original owner to have them remove this device from their account''.

So I did, I messaged the original owner and asked her to help, but she is not answering and I'm freaking out, because I am studying abroad and I REALLY need my phone, ASAP.

What other options do I have?

Thank you!