Is there any way to recover an Apple Account after a recovery key and trusted number were changed?

I've used the same Apple Account for about 12 years. Recently, I received an unexpected Apple verification code, followed by alerts saying that a sound was played on my iPhone, Find My was disabled, a new recovery key was enabled, my payment cards were removed from Apple Wallet, an unfamiliar trusted phone number was added, my password was changed, and I was removed from my iCloud Family group and calendar. I can no longer sign in normally.

Apple Support told me that the recovery key prevents them from bypassing the new security settings and suggested creating a new Apple Account, even though I'm still signed in on my iPhone and computer. I've changed passwords, cancelled my cards, secured my other accounts, and backed up my photos to an external drive. However, photo syncing was disabled, and I'm worried the person who took over the account may still have access to my iCloud data.

I had two-factor authentication enabled, which is why I received the unexpected verification-code text. Are there any legitimate recovery options left, such as using one of my still-trusted devices, or is the account permanently lost? I mainly want to regain control and remove the unauthorized person.