I think most people go for something feminine and sexy if writing hetero porn, and something masculine and powerful sounding if writing gay... but I'm not convinced that it's enough to turn off readership in any large quantities.

Here's my take on why you're not getting sales: your books aren't listed under kindle unlimited. They are short, which is fine, but without kindle unlimited, this means the only thing people have to go on is the 10% look inside - I looked inside a few and wasn't gripped, but since the books are so short, I only got a paragraph or two to judge your entire story on. Would I consider borrowing a book like that? Yeah, sure. Would I spend $3 on it if I'd never heard of the author before? Probably not.

Furthermore, your entire book is in 5 volumes, each priced at $3 and not borrowable - this means for someone to get the whole set they have to spend $15. For many people that's a really serious investment - for $10 a month amazon offers a literally, unlimited amount of books, including thousands of erotica titles. So why would someone pay $15 to get your complete story when they can pay $10 for a solid months worth of reading?

At the very least you could bundle your volumes up into one bundle for $4.99 and this would be much more affordable, but I would definitely urge you to look into Kindle Unlimited if you're planning on writing shorts as I think a great deal of erotica readers have unlimited now, and are quite happy to check out new books and authors under this system. If not going for unlimited, when you launch your bundle, you could put the first book free and then people will get a proper taste for your writing, and be more inclined to buy the whole set.

You could also set up an author page, I don't think this will affect sales much but it's a nice thing to have so that people can get some information about you and see all your books presented nicely (this needs to be done for multiple regions, but I checked both UK and USA and couldn't see one)