Boyfriend paid a service to get into my iPhone 11 Pro Max. It supposedly gives him everything I’ve ever done on my phone.

My boyfriend supposedly paid a service to access my iPhone and iCloud. Keystroke and backups of everything on my phone, even deleted things. What can I do to combat this intrusion and make sure it doesn’t happen again? I don’t know how long it’s been going on, so my computer backup could contain this same problem. Don’t know if it’s malware or what it could be.