How Do I Create a Loop Which Iterates Every Second.

Without knowing exactly what you are trying to do I can only give you generic advice.

Some basic testing will show that the loop approach you have taken will not work.

Create a basic scene with two objects. I chose an icosphere and a cube.

Using the logic with a timer inside a loop will not work as you might think. The after 1 second…means that after 1 second…you will continue to next itteration. That means after 1.1 seconds..it will automatically continue but before 1 second it will hold and wait.
The timer is NOT unique to the iteration but unique to the project as a whole.

You might be more successful using a set timer with an interval of 1 second and a repeat of 3.

There are other approaches depending on the memory requirements of the loop and lots of testing to validate if you should execute the loop or if the prior loop is done before firing the next. All of that is dependent on your project.