So I read post after post thinking that maybe discussing this with your wife and a therapist who could provide some mediation might help, until I read your post that your therapist isn't exactly helpful or knowledgeable enough on autism. There goes that suggestion...
I think you will indeed be going through several states now that you've self-diagnosed. I can't tell if it's best to let those stages run their course before you start the assessments for an official diagnosis, but I found the assessment extremely stressful and challenging, and it really helps to have a bit of emotional stability when you enter this stage. I'm confident you'll find answers to a lot of your questions, find questions you hadn't ever considered, and much more, including support and a sense of understanding. That should help you settle down with your newfound identity. Maybe your wife has trouble understanding that this is a label, or actually an answer key, but it will not change who you are, because your brain has always been like that. It's not a mental disease that might appear one day out of the blue and change everything. It is not new. The way I see it, it could be somewhat akin to a kid who knows he was adopted (the same way you probably always sensed that you were very different from other people), and one day they find the name of their biological parents (the way you found why you were the way you were). Is it going to change what that person has been so far? No. Would it be something that can be used as an excuse to do/skip things? Why the heck would it? Maybe it's me being confrontational, but when somebody tells me I might use autism as an excuse, I can't help but ask them why? Would
they, if they were in my shoes? And what in my behavior makes them think that I would do that? They usually can't come up with a proper answer. I've said it before, and I'll say it again, and again, and again, explanations are not excuses; but for a lot of people, they are the same. Probably because those people work that way (in which case, too bad for them, but most Aspies actually can hold their own without needing excuses... although we have a tendency to be misunderstood).
I would wait till all of this settles down a bit for you before discussing it with your wife. I totally get your enthusiasm, you found the last pieces of a puzzle and you want to show the full picture. You just need to wait for her to be ready to see that picture.
Another thought, when I told my boyfriend after more than 10 years together about Asperger's, he probably didn't connect ghe dots at all. When I told him about it again a few years later (by then, we'd moved in together), he was shocked -and I was surprised that he wouldn't remember big news like that. And he was extremely difficult for several months afterward, as if I had hidden some major flaw from him (I'm not damaged goods, and I didn't hide squat, I just didn't always know what to call it), I would say almost like I had betrayed him somehow. Sometimes, I would have trouble doing something, without any relation to AS, and he'd go "Don't say it's because of AS, you can't hide", which I felt was uncalled for because I hadn't even linked the failure of the day with AS, but apparently, that's not how everyone feels. Then he got into a brief stage where he had to assert his superiority in normalcy over me, which I guess made him feel better somehow, I just don't see how. And then I managed to have him listen to the good things about it, too. Got him to read a tiny bit about the traits and challenges (still not enough if you ask me, but I'm getting there). And now I'm working on getting him to take the online tests, because it turns out I'm most likely not the only neurodiverse person in this household of 2
Maybe you could check the 5 stages of grief. Sure, you're not mourning the death of an actual person, but figuring out who you are implies realizing who you are not/cannot be, and it is something you have to let go of. Your wife will probably be going through similar stages for different reasons, even if the reveal isn't as big for her as it was for you.
OK, now I'm stressing out over the next time somebody offers birthday cake. Is it going to be cake cake, or the other type of cake?
Although, cake by the ocean or sex by the ocean, honestly... either way, there's gonna be sand everywhere, so they're equally terrible ideas.