I went through a lot of that kind of frustration many, many years ago so I can certainly feel for you. Stick with it. It gets easier.

I’m surprised you didn’t include Smashwords in your comparison of ebook platforms and distributors. Not only is their platform by far the easiest of any that I’ve ever tried (and I’ve tried several) but their guidebook is super, super easy to follow. What I like best about them, though, is that they distribute your ebook to just about every bookseller in the world (and libraries, too). I always sell more ebooks through Smashwords than Amazon. Another thing I like about Smashwords is that they no longer have any payment threshold. If you only make 69 cents in a month, the next month you get paid those 69 cents. (They also offer free ISBNs.)

Of course, that’s true with Amazon KDP, too. I’m not sure what Amazon KDP you use with its 100 dollar payment threshold but the Amazon KDP I use has no payment threshold. They, too, will deposit 69 cents directly into your bank account 2 months after the month you earned it in.

For print books I quit using Lulu many years ago. I don’t know how they are now but back then they sucked big time. I prefer Amazon’s CreateSpace. They are 500 times better than Lulu.

Good luck with your endeavors. May you stumble upon a bestseller.