"I have not written any tests for any of my work yet. I am writing all the POD first, then I will get to the tests, eventually. The last time I looked at the Test suite of modules, I got so confused on their usage, that I just quit trying."

Thing is, if you get all of the POD done, then write tests, what happens if by writing tests you find glaring issues, and you need to modify the public interface? You now have to scour all of your documentation to ensure all examples, usages and explanations get updated as well.

To be honest, I feel that test cases are the best practice for confidence. You get familiar with the process, but it also allows you to have a closer relationship with your code (as you're usually bouncing back and forth from the test and the code).

"It will be especially hard to write tests for the modules I wrote and do not use."

If you don't use them, they are the perfect modules to learn how to write tests against. Nobody else is using them either presumably, so if/when you find glaring bugs and problems, you already know the code isn't in production anywhere. Not so much for writing code for modules already in production.