Very cool that you are doing this!

May I give you advice as someone who buys a lot of e-books? A book is judged by its cover. Your covers look really cheap, and so everyone will judge the quality of your book in that fraction of time.

It's like a funnel, and a lot of people will already drop off by looking at your covers. Bad graphics, bad fonts, bad colors.

Hire a really good designer and let them make the cover. It doesn't have to be expensive. I'm 99% sure it will make a ton of difference for your sales.

Maybe try it with your best book first and see what it does to your conversion rate.