How do i disable shift lock in this script when i normally walk without the tool?

So this script was supposed to be an ShoulderCamera for a tool.More specifically an weapon, a gun. So i tried multiple times edit this script but nothing really worked.Basically i want this shoulder script to work only while using the tool, or aiming with it.

Here is my script:

https://shrib.com/#Adrienne7vEoEer

Disclaimer: The reason why i put a link there is because the script is too long to be published here.