How do I handle being noticed only when something goes wrong at work?

You keep the whole place running, and the only time anyone notices is when something breaks. When it all works, which is most of the time, you are invisible. That is the strange injustice of essential work: doing it perfectly makes it disappear. It is no wonder the invisibility gets to you. Understand what is actually happening so it stings less. People do not notice smooth things, they only notice friction. The silence around your work is not a lack of value, it is proof of how well you do it. Every day nothing breaks is a day you quietly succeeded. Learn to read that silence as a scoreboard only you can see, rather than as proof that no one cares. But you should not have to keep score entirely alone, so make some of it visible on purpose. Every so often, tell your manager plainly what you prevented and what you keep running. Not complaining, just a clear picture of the machine you maintain. And find the few people who do understand and let their recognition count. You cannot make everyone see the backbone. You can make sure the ones who matter know it is you holding it all up.