For me, I found reading Honeybee extremely impactful when I started questioning my gender. Seeing someone go through the same struggles as me and having the same thoughts helped push me to finally visit my local gender clinic and start transitioning.
Whipping Girl early in my transition. It was really eye opening to read about the possibility of my trans identity being something other than a source of shame. It was the birth of my trans feminist path
Further along, Detransition Baby. That one hit me really hard. Close to home in some ways, but even when it wasn’t, it felt authentic. Trans literature for a trans audience.
I love literature for and by trans people. The first time I really felt seen in that way was when I read Small Beauty by Jia Qing Wilson-Yang. You can just tell that it was written by a trans woman with lived experience. Trans stories written by cis people just have different vibes.
It may sound silly to some, but “Guilty Gear Strive” - i.e. Bridget - was very important to me. Once I realized that I was envious of a character from a game who could have something that I had not (a transition), it was the final crack in the egg. If I wanted to have what Bridget had, I had to pursue it IRL and I do since then.
Onimai (anime) definitely got my brain churning and thinking about what I want in life, and that I’m not happy about my body in multiple ways
Edit; ohh, somebody else mentioned BNA(anime: Brand New Animal). That’s a good one too.
Plenty of webcomics too, Misfile, another I forget the name of (guy gets turned onto a magical girl by loki, untransforms and is… still female.), SuperNormalStep (diverse cast, AroAce MC), Kill 6 Billion Demons (just… holy shit. And unholy shit.). I’ve read a LOT of webcomics now that I’m thinking about it 😶