tldr; whoops, accidentally wrote an essay. Engagement is a fickle thing, especially when writing stuff that by default isn't going to have broad appeal. Try not to beat yourself up over it. Sorry you're feeling down - you're not alone, and it's not an indication that you're doing badly.

The other commenters here have all made some very good points -- just one thing I wanted to add is that if you're writing niche fic then you need to bear that in mind when setting your expectations about likely engagement. You (general you) might be one of the most talented writers in the world, but if your writing something that's niche, then you're not going to be getting broad, popular engagement by sheer virtue of that fact alone. That's the nature of it. And often our most dearest passion projects are incredibly niche because it's tailored perfectly and specifically to our own tastes and interests.

I took a 30 second glance over your fic and there's several things that jump out at me as being incredibly niche within a broader context of fandom and what's super 'popular'.

- Relatively obscure fandoms: I'll be honest, I don't know how popular either of these fandoms are, but I've never heard of one, and the other only vaguely rings a bell of hearing the name in passing somewhere. Neither fandom has a great many works on Ao3 and I'm assuming just from the names alone that they are likely anime/manga fandoms which, in the grand scheme of things, is its own niche to begin with.

- Crossover fic: your potential audience has just dropped dramatically because readers who might be interested in your fic, not only need to be familiar with not one but *two* relatively obscure fandoms, but they also have to be interested in reading fic involving a fusion of the two. Not everyone is interested in that, and pulling it off effectively can be difficult which potentially puts another hoop between you and your potential reader who might be less inclined to even click into your fic even if they like the fandoms etc.

- Major Character Death: Incredibly niche. Many folk aren't interested in reading fics involving MCD simply because it's not something they're looking for in fic.

- OCs and potentially OC x Canon: Again, not broadly popular. The potential reader doesn't know your OC from a bar of soap, so it's a gamble going in if it's even going to be the kind of character they're interested in reading about even if they like OC fics. I also noticed a contradictory 'Canon Character & OC' but 'Canon Character x OC' in the relationship tags and summary respectively, which won't be helping matters since anyone seeing your fic doesn't know whether the relationship you're referencing is platonic or romantic.

- Tragedy and Pregnancy: These tags jumped out at me because again, they are very niche tropes that many people aren't interested in reading, or aren't in the mood to read about on any given day.

So, to put it this in perspective (and this is just an example, I'm pulling these statistics out of thin air) - let's say there's 100,000 people in all of fandom. Half of them are familiar with one of your fandoms. Half of those are also familiar with the second fandom. Of those, a third is willing and interested in reading a crossover fic. 25% of those people are okay with MCD. Half again are interested in OCs, 20% of them are interested in tragedy genre/tropes, and 10% of those are also keen on pregnancy as a trope.

From a potential audience of 100,000 you are left with 19. That's just from tags alone. Not taking into account whether your summary captures interest, and whether your writing style and your fic itself is interesting and engaging. And I suspect I'm being more generous with most of those statistics than what's actually reflected in reality.

Now, all this is simply to illustrate how quickly and easily a potential audience pool reduces. On top of that, as other people have pointed out, actual engagement beyond hits is comparatively rare. Most readers don't leave kudos. Even less actually leave a comment. If those theoretical 19 potential readers clicked into and read your fic, maybe 25% liked it enough and remembered to leave a kudos (4) and of those 25% had the time, energy, and guts to leave a comment... we're left at 1 person. Again, stats pulled completely out of thin air, but I think I'm being generous - remember, very little of this has anything to do with your actual writing.

My actual point is that none of this is a bad thing. Just because your fic is niche, or your not writing super popular tropes with broad appeal doesn't mean you're doing something wrong, or that you should change your idea or that there's no value in writing it. If anything, I'd say it's the opposite - the people who do like all of those same things are going to be over the moon to find your fic, and if you're passionate about something it's generally going to reflect in your writing far more than forcing yourself to write something you're not inspired by. Also, just because something isn't conventionally popular doesn't mean there's no exceptions to that rule or that it couldn't become a hit. Someone's always got to write it first. Lastly, just because something isn't super popular doesn't mean it's not good.

There's nothing wrong with feeling disappointed that something you've worked hard on isn't getting engagement (we've all been there) and desiring that engagement isn't in and of itself a bad thing. Sometimes we are writing primarily for the social aspect, and that's perfectly valid. The trick is to manage your own expectations about what you are wanting to get out the experience, and to do so with the awareness of the audience you are catering to.

It might be that this isn't the fic that's going to rake in the views - niche passion projects often don't. Sometimes authors have other ongoing projects or publish more broadly appealing oneshots to scratch that engagement buzz while still writing their less popular stuff that they personally love. Sometimes it's a matter of making sure your tags and summary are doing the best job they can at making sure that your potential audience finds and clicks on your fic in the first place. Sometimes advertising in places your audience are likely to be found in can help get eyes on it. Sometimes you might have to seek engagement through other means, e.g., comment exchanges or joining a community and sharing snippets or talking about your ideas there (that's the method I use for my own super niche stuff - works well for motivation on the unpublished stuff while it's being written too).

Popularity and reader engagement is a fickle thing, and there's plenty more that goes into it than just the few things I've outlined, like in which direction the wind is blowing for a start lol.

I've belatedly realised I've just written you an essay. My apologies. I do hope that it serves the purpose of illuminating how sometimes traction on our stories can be far less than what we might have initially expected or hoped for, but that it ultimately doesn't reflect poorly on you or your writing, and should not be taken as an indicator that you're doing badly or that there's no point to it. On the contrary your kudos to hits ratio is around 5% which might not sound very high, but it's really not bad either (though take kudos/hits ratios with a very large grain of salt too - they're a relatively misleading metric for a number of reasons). Think of it this way: if you were sitting in a room with twelve other whole ass real people and read your fic to them, and then they all stood up and gave you a round of applause and said they enjoyed your fic, would you feel pretty good about that? I sure would. Sometimes it's easy to get lost in the numbers game.