You've got a keylogger of some sort on either your phone or your PC or you have an app installed that's been compromised. Every time you change your password, they are capturing the new password and the cycle continues or this compromised app is gaining access to your IG and following people who've paid for likes from bots.
Run Avast, MalwareBytes, etc, uninstall dodgy apps and then change your passwords (Email, etc)
Run Avast, MalwareBytes, etc, uninstall dodgy apps and then change your passwords (Email, etc)