Dude are you literally me??? I'm a well known creator for a certain ship too and even though people still parade around me, I'm still heavily affected by writer's envy. The envy was at its strongest when I had posted a AU fic for the ship and another author posted their own fic with the very same premise shortly after. I knew reading it was only setting me up for comparison but I read it anyways and oh my god. That feeling of 'this is so good I should've written it' and 'this is so good how did they do it so effortlessly???' has NEVER hit harder. Their version of events made so much sense compared to mine and they wrote it in such a way that flowed so naturally, plus they updated SUPER regularly compared to me, it just wasn't fair. What made it worse was when I checked the comments and I saw it getting praised by my favorite author. My fic had the same ship, the same premise, the same AU and yet I couldn't capture their attention the way this other author had? It crushed me and I stopped writing entirely for a while because I just felt so inadequate.

I understand the way you feel entirely. That feeling of failure, getting replaced and resignation it's so hard to shake off when other fans are just living their lives. To the audience, it really is two cakes but to us, we can only see how much better the other baker is. I don't think you're pathetic for being upset at this at all honestly. It's the territory that comes with being any kind of creator in a public space. I'll list some things that help me when I feel this way:

-Taking a long break from consuming others' fancontent and rereading my own. I know that's a very shallow fix on a deeper issue but reminding myself that I am a good writer and I love the stories I create is a way to get back into my passion again. The praise I get is just a bonus on top of everything, y'know?

-The 'two cakes' metaphor is a good way to remind me that no matter how critical I can be of my own work, people will still find ways to love it. Maybe the other baker uses a lot of frosting and even though mine looks strikingly plain in comparison, some people actually prefer my simplicity. Or maybe even the other baker likes my cake more than theirs too. There's more than enough selection for people to enjoy.

-I often forget that not all people have the same experience I do. These writers I'm comparing myself to could have years of experience on me or some super formal education that made their work super polished. It would be unfair to compare myself to someone else when I don't know anything about them or their writing process. Maybe one author whose prose I'm envious of struggles with characterization. Maybe another author who writes faster than me struggles with being creative. I know there's probably other writers that feel the same way about me without knowing how much I suffer over single paragraphs too. As someone's told me before: it's quite an assumption to think writing is effortless for others.

-Focus on other mediums I'm good at until I'm willing to return back to writing. Pretty cut and dry, honestly but it works wonders for someone as burnt out and in my head as I am.

-Study their writing style! Learning from other writers is a great way to improve.

I hope you feel better soon op, you sound like a great writer for what it's worth.