Bash – sourcing a Bash script – Return on Error, instead of Exit

I'm sourcing a bash script in the terminal, so exiting on error with

set -o errexit

kills my terminal, which is EXTREMELY ANNOYING, because I have to close the terminal, open another one, and reset some variables.

So far, using

command || return

lines, in the script, is doing exactly what I want

set -o errexit

to do… But I want it done for the entire script; not just one line/command

I have a file full of commands for setting up a site, and I'd rather not do command || return

for every single line in the file

Is there another set option, or something else that will just "return" instead of exiting the terminal?

— Just for clarity, I'd like to kill the script, and leave the terminal in the same state that pressing ctrl+C to kill a service running in the terminal would. command || return does that. But I don't want to tack on || return to every line in the file. So I'm looking for something similar to set -o errexit, that doesn't cause the terminal to shut down

— Note:
Creating a dumb script with two lines in it (super.sh):

create_path=~/Desktop/site_builder/create.sh
source $create_path blah

And placing set -o errexit at the top of create.sh,

works exactly as I expect it. However, it's really stupid to have to create a file with two lines in it, just to call another bash script, instead of just calling it from the terminal. Ugghhh

here's some examples:

in super.sh

#!/bin/bash

create_path=~/Desktop/site_builder/create.sh
source $create_path blah

in create.sh

#!/bin/bash
set -o errexit
#line below this is a line that fails and will cause the script to stop and return to the terminal as expected 
sed "s/@@SITE_NAME@@/$dirname" 
~/Desktop/site_builder/template_files/base.html > ~/Desktop/$dirname/templates/base.html # a line with a stupid error

in the terminal:

 $ bash super.sh

output as expected:

my-mac$

This works. What an annoying solution.

I want , ideally, to execute what's in the stupid super.sh file from the terminal, not the super.sh file :D, without having the terminal shut down on me. This is what happens with what I'm trying to do:

terminal command:

my-mac$ source $create_path blah

in create.sh I still have set -o errexit

Here's the output on the terminal

    sed: 1: "s/@@SITE_NAME@@/blah": unterminated substitute in regular expression
Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.

[Process completed]

And then the terminal is frozen. Ctrl+C doesn't work, neither does Ctrl+D

If instead of set -o errexit , if I just use command || return statements everywhere in the create.sh file, then I get exactly what I want , while executing the lines in supser.sh directly on the terminal (instead of calling super.sh from the terminal). But that's not a practical solution either.

Note: I liked @terdon 's answer about just spawning a child shell
so I ended up just spawning a sub shell via the script instead of the terminal, as he showed in his answer using the braces ( ), around the entire script.. His answer works too.