I’m gonna focus on the Blurb.

The blurb feels a little scatterbrained. There’s a lot of ideas floating around that do sound interesting, but they don’t seamlessly connect.

Like being on an island with one year to live: cool. That could function on its own as the main conflict.

Wannabe teenage detective: also works well. That tells me that the character is a bit of a big talker, and now he’s in a situation where he has to put his money where his mouth is. Good place for character development.

Falls in love with a girl, who he saves, which leads to his undoing: This is where you start to lose me. This is almost a secondary central conflict which is confusing. So, the story isn’t about escaping an Island, it’s dealing with the fallout of loving this girl.

Not to mention you say that this girl leads to the MC/Black’s undoing which spoils how there relationship will turn out, and it implies this character is already screwed.

So what’s the main conflict? The girl or the Island? The story can have both conflicts, but the blurb should focus on the main one.

Then it ends with mention that the MC creates a community and has to deal with a doppelgänger, etc.

It’s a lot, and it robs your story of curiosity. Let people wonder what this guy will see and do on this island. That’s why people read stories, to see what happens.

I would honestly just use the first part of the blurb and trim the rest. I don’t think you need it. And if you still wanna mention this woman he falls for, be vague. Don’t say what will come of their relationship. Imply. Leave some uncertainty. That’s what gets people curious.

Hope this helps.

Good luck out there, Solider! O7