Autistic husband

I'm the autistic one in my marriage, honestly it took a long time to get used to having to share a bed at all, the presence of someone else there turning over, leaning up against you, subconsiously stealing the covers in the night leaving you freezing, or snoring in the night is horrific when you are hyper sensitive to pretty much everything and just want to turn your brain off and sleep.
We had to fix this through trial and error over the best part of a decade and in the end turns out I don't have a "sleep disorder" it was just autistic hypersensitivity that had to be rectified by the following:

1. Other half wears nasal strips and accepts being rolled over with 0 warning.
2. Using a soft matress topper. (It might need to be put on upside down if it has a texture still feel-able through the sheet.
3. Going through a variety of pillows to find the best material and neck support.
4. Call time at the bar on romance after saying "goodnight", no cuddling, no petting, no touching of any kind after a certain time, sleep time is sleep time.
5. The bed isn't kingsize but the Duvet is, having an extra foot of duvet can be a big deal if one person tends to roll with their edge to the far side in their sleep.

As for retreating, that's really mostly because he probably doesn't feel like he'll be allowed the same peace and quite in the rest of the house, you'll have to devize a fix for this that works for you and your family but mine was an agreement with everyone else that they must keep the volume down and leave me alone for no less than 3 hours on a weekend and everyone else must go to bed/go upstairs at least a full hour before I need to so I can unwind in solitude. That way I can watch an evening movie with everyone on the sofa and still get alone time.
When going out I also get overwhelmed and not letting me escape before it gets to boiling point would always result in a meltdown, sounds weird but we now have a safeword for social situations where I get to just go back and sit in the car or for things like theme parks a predesignated regroup spot (usually a cafe or nook out of the way of most rides and through traffic) no questions asked while everyone else does their thing and then I rejoin them after I start feeling better again.
Maybe that's stuff you can try to adapt for your needs?

I'm the autistic one in my marriage, honestly it took a long time to get used to having to share a bed at all, the presence of someone else there turning over, leaning up against you, subconsiously stealing the covers in the night leaving you freezing, or snoring in the night is horrific when you are hyper sensitive to pretty much everything and just want to turn your brain off and sleep.
We had to fix this through trial and error over the best part of a decade and in the end turns out I don't have a "sleep disorder" it was just autistic hypersensitivity that had to be rectified by the following:

1. Other half wears nasal strips and accepts being rolled over with 0 warning.
2. Using a soft matress topper. (It might need to be put on upside down if it has a texture still feel-able through the sheet.
3. Going through a variety of pillows to find the best material and neck support.
4. Call time at the bar on romance after saying "goodnight", no cuddling, no petting, no touching of any kind after a certain time, sleep time is sleep time.
5. The bed isn't kingsize but the Duvet is, having an extra foot of duvet can be a big deal if one person tends to roll with their edge to the far side in their sleep.

As for retreating, that's really mostly because he probably doesn't feel like he'll be allowed the same peace and quite in the rest of the house, you'll have to devize a fix for this that works for you and your family but mine was an agreement with everyone else that they must keep the volume down and leave me alone for no less than 3 hours on a weekend and everyone else must go to bed/go upstairs at least a full hour before I need to so I can unwind in solitude. That way I can watch an evening movie with everyone on the sofa and still get alone time.
When going out I also get overwhelmed and not letting me escape before it gets to boiling point would always result in a meltdown, sounds weird but we now have a safeword for social situations where I get to just go back and sit in the car or for things like theme parks a predesignated regroup spot (usually a cafe or nook out of the way of most rides and through traffic) no questions asked while everyone else does their thing and then I rejoin them after I start feeling better again.
Maybe that's stuff you can try to adapt for your needs?