Aspie partner

Hi from London !

I hope everyone is well. I live with an incredible “Aspie”, still not been diagnosed. But a few years ago when reading about how Helena Bonham Carter discovered that Tim her husband at the time was an Aspie, I read and read about it then with my partner. He cried and had a sort of almost relief that he finally understood l, at 30 years old, who he was. But we never really spoke about it again. I was hoping he would go himself to get diagnosed. He never did. Fast forward 5 years later, we have an amazing child and I’m waiting for baby number 2 due in September.  I have been living incredibly amazing and fun and creative moments during lockdown as well as his regular “monthly angers” that have been hell. I read here on some posts that those episodes are called “Aspergers tantrums”. They used to be way worse as he would break things in the house and really explode (a window , his phone, any objet like coffee mug or anything near”). Then he started calming down as our son grew up scared of these tantrums. Terrified. What annoys me is that he was always so calm and sweet after and also that he never harmed us physically I mean. He would just always explode around us. So I always thought it wasn’t that bad. But now that baby 2 is here in 3 months, I’m extremely worried and sad that nothing has really changed. 
today, SINCE THIS MORNING, he woke up with that face of his bad days. So I asked our 5 year old to stay as much as possible in his room and we avoided him. But this evening, he picked on a subject and WOULD NOT MOVE ONTO ANY OTHER SUBJECT. Just to get in a fight. I promise I adapted my techniques. I remained calm and ope . I eventually asked him “what exactly are you trying to say here” and it got worse. I’m pregnant so these emotions hurt my tummy sometimes. So at some point I said “ I’m in pain in my stomach so I’ll go to read a book then sleep”. But he’ll probably continue tomorrow morning until he explodes on me or the little one. I’d rather it be on me. I’m so tired. I want this relationship to work and there’s been progress. But I’m SO TIRED. I’ve read here testimonials about how some partners ruined the life of their partners. And they ended up exhausted at 50. And the person never really tried to evolve or make things better. 
My partner is a genius in his job, he’s one of the best. His parents too are Aspies I think, and they’re brilliant in everything they do. Everything. And they have the same obsession for some subjects. And they have the same seemingly emotional disconnection sometimes (not saying no feelings but just a seemingly disconnection). Bad sensory days (mine would be with sounds : our knife on the plate in the mornings, our voices, music on the record player or worse ANY SMELL !!!!). So my partner doesn’t feel he needs to change or needs to really work on anything. I don’t want to lose our family or give up. What is your best advice ? He asked me last month after a tantrum of his and me ending up in tears he asked me to help him find help as he doesn’t know where to look. What is the first step ? What is your advice ? What should he do please ? PLEASE ? Thank you. 
Lovingly,

L.