The first mistake you're making is trying to be better than Trigun. Not because Trigun is particularly great, but because you're focusing on other works instead of your own. You'll never be them. They're their own works and they're own story. They're all "desert of doom and scarce resources", but each of them aren't telling a story "the wastes". There is no "the wastes". There is only the aesthetics of a waste.

What's important isn't what you're doing. It's how you do it. What's important to Raze? What makes Raze matter to you? What is that story you want, even need to tell? Focus on that. Stop thinking about those other stories in terms of them being better or a paint job. Thing about what makes these characters and this world special. What is the story you want to tell?

I am actually reminded of a similar piece of advice, that basically says what you say there.

"Don't try to be 'The Next (X)', be 'The First YOU"!

Is that what you mean?

In essence, but more detailed and less punchy. It's good advice, "be the first you", but it misses an important nuance.

Completely original ideas are basically impossible. We all know what super heroes are, what armies are, what the future is as a concept. It's more accurate to say there's no such thing as an original concept. But there is original stories. No one will tell a story of someone lost in the wastes the same way. That's *why* there's this huge list here that Chris presented. None of these people were trying to tell the story of "the wastes". They were all telling their stories, and their stories happened to take place in a waste.

A good story isn't about seeing a place you've never seen before, but seeing a world you've never seen before. And that comes down to the people and what they're doing in it, not how many nukes went off or what disaster ruined the earth. How someone is dealing with the situation is way more important that the situation itself.

They're great inspirations, but you don't have to be them or be better. Just put your twist in on what you know. (Of course, that Twist is BIG lol X3)

I'd say, try not to be better than Trigun, make the story you feel like you want to make.
It's understandable when being inspired by a show, movie game, etc. Just like Shady said, you don't have to be them or better.

Make the story how you want it to be made. TheConflicted and ShadyIMG have some good points.
I wish you luck with your story mate.

your treating trigun as main ingrediant when it should be base or a broth take what you want from it and build from there

Nearly two and a half millennia ago, it was said, and known:
"What has been will be again,
what has been done will be done again;
there is nothing new under the sun."
Ecclesiastes 1:9

Trying to be wholly original is overrated. Your only obligation is simply to avoid outright plagiarism. A world will be "yours" after you've created it; the simple act of creation imparts the author's worldviews and sensibilities onto the creation, making it unique from other works, even if only subtly.

As an exercise, can you tell me which of the works you've listed have "copied" from each other? Which ones are, say, "'Mad Max' with a fresh coat of paint?" Perhaps that will give you some fresh perspective.

Otherwise, the only qualitative advice anyone can ever give for "better writing" is to keep "reading" (or watching, or playing, etc.), so that you can develop a critical eye for what does and doesn't work... And why something does or doesn't work, be it a story in its entirety or an element of one.

If a story is genuinely frustrating you, just shelve it; you don't have to kill it. Especially if your livelihood doesn't depend on it. Come back to it when you're inspired to do so.

Okay! So!
First thing I'd advise you to do; figure out your main characters. there's a template that almost universally helps make up a story and it boils down to 6 questions:
Who is it about?
What do they want?
Why can't they get it?
What do they do about that?
Why doesn't that work?
And How does it end?
This video really helps go into detail about it: https://www.youtube.com/watch?v=F7i3w6XW_2Q

Essentially I feel figuring out your character's desire and the conflict that arises from it is what boils down to any real story. It's as simple as being stuck on the toilet and realizing there's no paper. (weird example, I know...but it's a conflict)

Also the last question is especially important from my point of view. You definitely don't need some cemented ending in mind but a general idea of where you want your story to go helps in the long run. As you connect the story beats whatever ending you start out with is bound to change in very unexpected ways to organically fit the narrative.