Have I been hacked

If running iOS 13 or earlier versions, check: Settings - Passwords & Accounts - Accounts - Any rogue entries here? If so, delete the rogue account. 

If running iOS 14, check: Settings - Calendar - Accounts - Any rogue entries here? If so, delete the rogue account. 

The Apple support article is below. 

https://support.apple.com/en-us/HT211076

Johnmiller2185 wrote:

How can I tell if I’ve been hacked?

there is no hack/virus/malware for a non jialbroken iphone.

What makes you think you've been hacked.

Good news, thanks for the feedback.