I think my phone is hacked. It’s sending texts to China or someplace

it's unlikely to be your phone, per se.

However, it might be someone else using your iCloud account - since iCloud is synced across all devices, someone sending messages while logged in on another device would cause the messages to appear on your phone.

Check https://www.icloud.com/settings/ to check where your account is logged in, and disconnect any unrecognized devices.

It is also possible that, if you're not using a supported carrier, you're seeing the charges for the iMessage/FaceTime activation messages.