What do you get out of this relationship now?.
What did you learn about relationships when you were growing up?
You are not soulmates (and that is such a hackneyed term).
Re your comment:-
"But what will I do if I leave him? I will be so broke and the only option will be to have a baby with a sperm donor and be a single parent".
Do not be so bloody dramatic here!!. Honestly that is not your only option at all, that is you catastrophising!.
He does not want what you want and so fundamentally you are incompatible. Your relationship with him is not as great as you make it out to be. He has and is telling you what he thinks; when someone does this you need to believe them!!!. I doubt he will change his mind and I would be very wary about handing over yet more power and control to him like you already have. Those concerns of his are deeply rooted, somewhat selfish (he is concerned about his sleep being disrupted so not yours then) and he also did not have a good childhood either. Pay attention.
You do realise you could be totally wrong here re him and HFA. What is your own understanding of this, what have you based this on? Panic attacks and health issues in themselves do not directly point to HFA; he sounds like a supremely selfish workaholic and what is he going to do with himself if he walks away from this business he has built up?. He may not ever walk away from this business. I can't see him run around after a child and do housework (also because you're already doing all the chores and why did you let that happen too?). You have sleepwalked into this life with him at great cost to you.
You made a comment to the effect you look after him (why because you are not his mother), in such circumstances do you really want to bring a child into this particular dynamic?. You will likely remain unmarried, become completely dependent with a child to look after making you even more vulnerable legally than you already are (your legal position already here is not great). You will continue doing the housework as you are doing now on top of all this.
What do I get out the relationship? I mean a lot, it's a very loving relationship. He'd do pretty much anything to make me happy (apart from give me a child so it seems ). We have a lot of shared interests and have a fun life together. We're both independent people too, and it's the first time in my life I feel happy and supported in a relationship. He hasn't a nasty bone in his body, he is a gentle person and deeply intellectual.
What did I learn about relationships growing up? My dad was abusive to my mum. She left him. I learnt that you don't stick around if you are unhappy so I guess that's why I am thinking that yes as you say, we are incompatible.
In terms of sperm donor, I think that is what I would do if I left him. I can possibly find someone in the future again. Remember I love this man, so leaving him would be heart breaking for me, jumping into finding someone else with my biological clock ticking away doesn't result appeal. I am just trying to run through my options really and this felt like the most obvious.
Yes I agree he is telling me that he doesn't have the same instincts as me.
Re HFA - my brother has Aspergers so I have been around this my whole life. He has so many traits, especially sensory overload and meltdowns. The focus on one thing - eg growing and selling this business - is another manifest. He is obsessed with retiring at 40.
I mean why did I let it happen? You are misunderstanding that I have a bad life when it's quite the opposite. I literally have everything I ever wanted apart from a baby. I also am not bothered about marriage, most of my friends are with long term partners and are not married.
Part of me feels like saying 'ok let's not bother' and then just commit to a child free life where we travel, have fun and do interesting things, maybe foster or adopt in the future. I also am Mindful the world is not a very stable place right now and will prob be even worse by the time they are an adult. I know a lot of people feel like this.