Unless your phone is "jailbroken" the likelyhood that you've been hacked is somewhere between slim and none.
If your phone has a 'phantom/ghost' touch and apps are opening/closing on their own, that actually means there might be something physically wrong with your display and you'll want to take it in for service. See Apple Support contact information below to get started.
Otherwise, make sure you have a strong password for your iCloud account and enable two-factor, so even if one were to guess your password, they would need a trusted device to access your account.
->Â If you think your Apple ID has been compromised - Apple Support
You can also completely reset your iPhone and return it to factory settings, if you feel safer doing so:
->Â How to factory reset your iPhone, iPad, or iPod touch - Apple Support
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Apple Support Contact Methods
-> Call Apple Support 1-800-APL-CARE
For International Numbers or ASL support, click here:
Contact Apple for support and service - Apple Support
-> Chat with Apple Support
Apple Support
-> Get Started Online
Apple Support