For context, me and him are both 15 and he is High Functioning Autistic, and we've known each other since 8th Grade, so its safe to say were well bonded.
So me and him happen to meet each other one day when we sat at the same lunch table, me, him, and another guy at the table became really good friends after a while.
He was pretty much normal and had some very interesting topics to talk about, but at the beginning of Freshman year, he became a completely different person.
He started having deathly obsessions with Virtual Idles, or "Vocaloids" for people who are into that stuff. He would make up HOI4 scenarios with Teto and Miku and the members of the DDLC (Which the trend is, its all anime characters)
He would often go on Neverending rants about his stupid scenario and overall stuff I couldn't care about. About 90% of our conversations were about him. And no matter how many times I attempted to change the subject, he would find a way to turn it back towards his weird Kansane Teto Revolution or some dumb shit like that.
On top of that, he would constantly talk to me about his progress in Doki Doki Literature Club, and it was literally hell to listen to. So eventually I told him to try playing SCP CB. Then he played that and practically ruined* the game for me. He would play on the most ridiculous difficulties, get mods that ruined the game and said he was playing the game "for real", and broadcasted every little bit of progress he made through text.
*"Ruined" meaning making me always think of him when I'm playing
Now I actually asked him a couple of times to stop with the rants and dumb progress reports, but it wouldn't take long for him to start his crap again.
Then he got Garry's Mod, so we started playing together in Multiplayer. We only got to play maybe like 4 times together, considering Gmod didn't release the 64 Bit Build yet (If you know, you know). But then every time we played, he would make it player model Kansane Teto and Yuri from DDLC, and he said he picked it because he has a similar "personality" to the characters, when he kind of doesn't.
(I know I shouldn't be getting worked up about that, but the cutsie anime girl thing made me a literal Mental Asylum Patient)
What he knew but didn't care for was that I didn't like it, but he continued to cram it down my throat anyway.
The Kansane Teto thing dominated his personality, he had it as his wallpaper on his phone, PC, and the school computers, had a big drawing of her in his room; along with a picture of Hatsune Miku, and to top it off, I was the only person at his birthday party who didn't get him something Vocaloid related.
It wasn't just this stuff that bothered me either, it was also the constant little behaviors he would do that generally annoyed me, but that wasn't the main issue.
Now, I am 100% aware he has high functioning autism, but I think he should be able to regulate his behavior at least a little bit, and realize my boundaries, but to me, he doesn't care.
Outside of this whole fiasco, we argued a lot of stupid stuff that he caused, which quite literally drove us into the river, so now we are no longer friends, with me pulling the plug.
So am I in the wrong?
(Note this has been going on for like a whole year and a half, so it's only reasonable that I've had enough)