I think, since it appears that this is a story about a slime... even if the art was in the most generic style possible, the fact that it was a really nicely drawn generic Fantasy cover... depicting a slime on an adventure would be enough to pique people's interest. So don't worry about not standing out. Even really samey looking covers often attract people who just read something popular and want basically more of the same so will click on anything remotely similar looking.
If you have the means to commission a cover, I'd advise it, personally. Ideally with an artist with enough design experience to do the typography for you. You've done a pretty decent job working on your own, but Tapas is super competitive, and I'm sure you've seen what the covers on the top performers here look like; how they have really sparkly, professionally-designed logos and really polished art with attention-grabbing faces and very fashionable styles tailored to the audience (mostly 20 year old women who like Korean webcomics or isekai webnovels). It's not that your cover is bad, but it's not optimal for performance on this platform or getting features (and features are vital if you're serious about building an audience).
My partner is a good illustrator, with an illustration degree, and even they commissioned a more fashionable, pin-up art focused artist to make their Tapas novel cover (Their novel is called Bard Romance if you're interested to see it), which really paid off.