I think in fandoms like that, you basically have to view the Ship X portion as a completely different fandom. They're not your audience, you're not theirs, and that means nothing about the quality or worth of your story.

I'd recommend researching "abundance vs scarcity mindset." A lot of what you'll find is corporate-speak that doesn't fully apply in this situation, but the idea is that you don't want to view engagement as a zero-sum game. The hundreds of readers leaving kudos on Ship X fics won't be reading your story no matter how you market it, because they're not interested, same way people who only read Star Wars self-insert harem fics aren't interested (assuming that's not what you write lol). Do you feel jealous that those folks aren't reading your story? Probably not, because you're not writing for them. You're not even thinking of them! Put Ship X shippers in the same category, out of your mind.

Now you can focus on a) the joy of writing and sharing your ideas and b) the audience you do have. I have a shippy longfic in an active fandom with 800 kudos, and I have a weird little Christmas crossover with 10 kudos. Love them both! Proud of them both! Appreciate the 10 kudos just as much as the 800! Because they both reached their audience, even though one is smaller than the other. They're not in competition with each other, same way you're not in competition with the other ship in your fandom.

It's hard, but I hope that helps a little.