Husband suffers from Schizoaffective Disorder

I'm newly married coming on two months on march 1st. My husband is an outgoing, caring, funny, Star Wars nut, Author in the making who loves cats, me and coming up with awesome names for our kids. We both have red hair and our friends tell us we're going to be the Weasleys. I have not idea why.
I love my husband dearly. But there are things that I don't know how to help him with. He doesn't sleep well, he can't relax, he's constantly complaining of a sore back, and he over reacts to my being passive. His mind races all the time and he talks very quickly and complains when I talk just as quickly.
I have my own faults too, so don't think i'm just up here complaining. I do talk too fast. I don't enunciate like I should. My grammar is horrible when speaking and I trail off if I don't have my thought ready. Sometimes I have my argument up and ready before he's done talking. I don't mean to but I tend to interrupt a lot. He get so frustrated when I keep saying I will work on these things I will do better and it doesn't happen. My intentions are good but how do I really practice not interrupting other than not talk till i KNOW he's done talking?
Maybe I am complaining a little.
Anyway, my point is that I need some strategies on how to help him relax without medication and get him to slow down. That's a huge problem with us both. We don't slow down, I can't keep my words straight and he can't keep his thoughts peaceful.
Any thoughts?