I think one of the biggest things when doing long stuff on the internet is to treat it like it's a long thing, a marathon run.
And to do that, you need to understand that it's a slow build for all creators--and several have started on different websites when they were like...children (and they might still be children, hence the bad grammar). If you're just starting out, it will be really low. Luckily, you have the talent to improve better than a child and you should have better focus and time management then a child, so you can surpass them, eventually.
Another thing to really get in your head now is that the spikes in growth that we see in other artists and writers are spikes. We see what goes viral, but we don't see how after a spike, you will have the other side of the spike--the plummet in views, the dropped subs, and the rate will go back down to where you were before, but a little bit better. Overall progression is slow and steady, so long as you stay consistent--the spikes are cool, but they aren't really permanent.
Then finally, make some concrete goals so you know when to throw in the towel, in case those goals aren't met. We can't become a servant of our works if they aren't really panning out, even if they're well written and a great time. If your goal is only improvement, then you'd only need improvement goals, which aren't dependent on subs and likes (though subs and likes help a lot!) If your goal is to profit off of your story and it isn't getting those views enough to make money in the time frame you needed...then yes, drop it and do something that will (but make sure if you do that you don't abandon your readers. Give them something to hope for--we want them to transition to your next work). Maybe this story will be better suited to a different website or a different publisher?
And like others have mentioned, having a marketing plan helps a ton--especially to think of it as a plan, so you aren't just shooting tweets out of your ass. Find out where the writers live, find out where your readers are at, find out who the influencers are that are reading web stories. It's a slow and steady climb, not a race, and what you're seeing as a failure is not. Every work we make is just a stepping stone to the next bigger thing.