Update: I don't really know what just happened but I think it is good? (sorry if these updates are annoying or stupid but i feel the need to write it out)
So basically he had been trying to avoid the conversation whenever I brought it up. He got a little loud and scary, but I was like "no man this is my chance to do this" so I spoke calmly. I think a problem is that he doesn't understand what a service dog is, because he said "the dog would have to be alone all day!!" and I explained that the dog would actually be with me all the time. And he is also 100% convinced that our landlord does not have to lift her "no pets ban" when the ADA law states that service dogs do not count as "pets" and must be admitted (which I sent to him), however he said "Fine, follow through with that then. Write an email to the landlord and send it to me so I can send it to her."
He said either way, his divorce from my mother is set to be completed in December (they separated like, six or seven years ago, maybe even eight), where we will have to move back into the house (yes yes I'm terrified but maybe it will be okay) and we can have a dog.
He was once again loud and looked pissed, but he told me he was just frustrated and wanted me to be happy. What was kind of funny was that I told him about my last dog's vet (which is right down the main street, not even a five minute drive away) and how their rates and care are fantastic, but I used the abbreviation and he thought I was talking about a trauma centre. He was going to ask my old therapist for a referral to a vet! That was pretty funny.
Anyway I think this is a good step so I'm going to write that email, sleep, and then edit it. Do you guys think I should attach a copy of the ADA law just in case?