I have managed to lock myself out of my iPhone 7

Follow the instructions here, you will need to put the device into Recovery mode. If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

Follow the instructions in this Apple support link—>If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

You need to connect it using the instructions as per section "remove your passcode" in this support article:--> If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled

Regards

Giulio