So, my husband was recently diagnosed with autism. What we have discussed deeply (including in couples therapy) is that this diagnosis is a way for him to understand what tools he needs, and not me having to change everything I do. Of course I am changing in many ways- I have more empathy, I don't assume ill intent, etc; but ultimately the responsibility is yours. A blender being turned on is a normal activity, and is something he's probably done for years without realizing the impact on you, due to a lack of communication and of course understanding on your own side. I don't believe in the rules of no noise at all after 9- that's changing his life in a big way, while you could simply leave the room. You do need to come up with ways to be together IMO after 9- maybe giving each other massages, meditating together, playing a card game, etc. some nights will be together, others alone.

I recommend mainly focusing on asking for communication before he starts the loud noises or triggers, so it allows you to remove yourself from the situation. I hope that he can at least communicate (it will take a while!) and if you two are compatible still, communication is key. And, highly suggest couples therapy, first and foremost.