Sex and autism, question about how it can effect certain aspects of one’s sex life

Hi everyone, me and my partner are both in our early twenties and have been together for 4 years. We believe he has high functioning autism. When we first started dating he was pretty into sex, he’s never had a crazy sex drive, but occasionally will be more interested in it. We’ve had good sexual experiences together but the last half a year he’s been declining more and more. I know he was initially stressed about getting a job after university so that could have been a reason.

But after he got a job now he is finding a hard time with work life balance, there so much he wants to do, he does seem overwhelmed but when his mind is on something it doesn’t seem to shut off for months. Now we have not had really had sex in a month, and it’s concerning to me.

Has anyone with autism here had more interest in sex initially in there relationship and then it slowly declined because it was this new interesting thing? Or is it more that he is just hyper fixating on his life outside of the relationship and not worried about this stuff anymore. Unfortunately it does feel lonely at times when he is hyperfocused for months on either something or a feeling, but I’m trying to navigate it.