iPhone 7 lost service. restarted iPhone.(error 3) when re-booting from iTunes. stuck.

I tried rebooting my iPhone 7 after it lost service (Verizon). I went through iTunes to update the firmware and it gave me (error (#3) ). ive tried wiping it clean and then restarting it from zero and rebooting multiple ways and it is not letting me work properly. if anyone has an idea to troubleshoot and get it going, that would be great. I have a backup for my phone in iTunes, so im not worried if I need to "restore" from zero. the problem is (error #3) stops me from continuing. I have also tried it in different computers, and the same problem appears.