AITA for yelling at my autistic girlfriend for eating the same thing everyday

Hey quick heads up I am the autistic girlfriend however I'm writing this for my boys who is convinced he's in the right so yeah

So basically I am autistic and I struggle to change my routine so to prevent meltdowns or feeling out of control I eat the same thing every morning which is porridge I know it doesn't sound like alot but as someone who grew up in a small British household a big bowl of porridge is alot, and recently my boyfriend has been staying over with us more and more, I noticed that he would sometimes give me funny looks in the morning when I ate but I never thought anything of it as he is not a morning person so I assume he was probably just grumpy how ever one morning I guess he really woke up on the wrong side of the bed and proceeded to tell me that "I have to change up my routine a little because im tired of you eating porridge." Now when he said this I thought he was joking so I made jokes like 'why would I can be my food when I have the perfect breakfast' but it became, clear that he was not joking when he said

“it’s not just about the goddamn food, it’s about your whole routine, it’s basically the same everyday. It’s your whole lifestyle that needs to change,It say it’s pissing me off." Now when he said this I was genuinely stunned because one he's never vocalized my routine being an issue for him and secondly it's not like my routine is unhealthy yes it is a bit repetitive but it brings me comfort,

To sum up my daily routine I get up I eat my breakfast which is 90% of the time porridge and the brush my teeth and stuff like that, I'll spend a bit of time on my phone I'll then do a bit of work on my sketches it it's not a day I have school, and then when I'm done with that I'll get up and go for a 30 minute walk I'll come home and relax sit on my phone maybe watch some TV and usually talk to my boyfriend until dinner and what's I eat depends on what my mum or older brother make as they both enjoy cooking the most and then I'll shower and spend the rest of the night drawing if I'm alone or watching TV with my boyfriend or reading, so its not a relatively unhealthy routine so i cant understand what his issue with it is.

But like he asked the next day I changed it up and had toast with ham and cheese and an apple and he had a big go at me for not eating enough which caused a massive argument because I was confused and really couldn't understand why what I ate was such a big deal to him because it's three slices of toast and an apple.

I'm actually at a loss and I don't know if what I'm eating is actually a big problem and I haven't even realised or if he's completely overacting for no reason

So what do y'all think is he the asshole or am I?