Finding a path forward in a possibly neurodivergent marriage

As a pre-preamble, I think part of the reason I'm writing this is therapeutic, but I'd love to have responses from other people, preferably those who have found good solutions to these issues.

Just to prevent any misunderstanding from what I'm going to say below, I'm going to say first that my wife of nearly 18 years is wonderful - she's kind, caring, beautiful, intelligent and I love spending time with her.  She's the most important person in my life, I respect her more than anyone else, love her more as the years have passed and want to make her happy more than anything else.  From the very beginning, I've felt like something was wrong with our relationship though.

At first I thought she was just shy and very sensitive about physical affection and intimacy, so we got help with that, which got us to the point where intimacy didn't cause pain and then as far as she was concerned, the problem was over and she wouldn't continue with us getting any professional help.  We did discuss whether her upbringing or any historic issues could have caused problems with the therapists, but nothing came of that, and her parents are very caring people and I'm sure that by now, I'd know if there had been anything like that after so many years. 

Over the years she has learned to be a little more physically affectionate and to enjoy physical intimacy a little more, but she can still be very sensitive, jumpy and every interaction, including the affection is very formulaic and always has to be initiated by me.  Intellectually, I'm pretty sure she loves me.  Emotionally, I'm finding it very difficult with the lack of affection, especially with the lack of her initiating it.  

She's never had any diagnosis, and although she scores well above typical neurotypical ranges in the aq/aspie quiz etc, she doesn't quite get into the ASD range.  I've discussed this with a psychologist who I've been seeing for anxiety for years and he says that it sounds like she has some autistic traits but probably isn't enough for her to be formally classified as autistic.  She's not very outgoing and finds socialising very draining, but she can cope, so for the most part there's nothing that obvious to anyone else.  She doesn't have any obsessions over specific subjects or anything like that.  She does seem to have some sensory issues in terms of physical affection.  She doesn't seem to get the idea that I need some kind of regular reassurance about how she feels about me.  She doesn't seem able to communicate very much about emotions - I've tried to have so many conversations over the years and she will just sit and listen and then wants to move on and won't respond to what I am saying without an explicit prompt for an answer, and then it is usually very unsure or vague.  If I'm upset, her instinct is to leave me alone.  I've got 3 autistic nephews and I feel like she has some things in common with them.  I also feel like her dad also seems to display quite a few traits that seem familiar - he seems to miss quite a few social cues (she doesn't tend to that much, but probably more than is usual).  

I find it very difficult to explain how it is hurting me so much.  I spend massive amounts of time looking for that reassurance about how she feels about me and sometimes feel unloved and even unlovable.  Sometimes I feel like a kicked puppy, but I know that's a bad metaphor because I know she would never be cruel to anyone.  I think that only someone else who has been in this situation can understand properly, but I've read enough to know that it is quite a common problem.

I'm not blaming her, but I feel like my mental health has suffered a lot over the years.  In some ways, I feel like from her perspective, I'm the one with the problem - as far as I can tell (which is mostly because I explicitly ask her), she's happy enough.  She rated our marriage as 8 out of 10 in terms of how happy she is when I asked her to.  Sometimes I wonder whether I'm being over sensitive and needy.  Other times I wonder whether even if I am "normal" for a neurotypical person, the neurotypical constant need for reassurance about how she feels about me is more broken than her lack of a need for it, and it makes me wonder if most people would be happier if everyone was autistic!  Then I remember how some autistic people who I know can be very determined that only their approach is correct and I think that can't possibly work - there would be too many massive arguments!

A few years ago I put my foot down and said that I wasn't happy and we needed to get professional help.  We went together once, then she went back a few times and declared that she had heard enough and just had to put it into practice.  It was going a bit better for a while - it was small steps, but she was occasionally asking me to put her necklace on her in the morning etc, which meant a lot to me, but then Covid lockdowns hit and things went a bit mad being shut in with 4 kids and we just put that problem on the back burner.

I've read a few books and we're working through the Eva Mendes one together.  I've also put together a 17 page document trying to explain to her what I feel like "normal" is from my perspective in a marriage, and what I feel like my needs are in quite a lot of detail, and she's part way through reading that. Some of it shocked her a bit, and her response was that a lot of it is completely alien to her, but then I feel like the way she seems to feel is completely alien to me.  Unfortunately we don't have that much time for these things as we have 5 kids now with a range of ages and we're very busy with them.  She does seem to be putting more effort in to show physical affection at the moment.  It isn't massive, and it feels a bit forced, but it means a lot to me that she is trying.  I am still feeling frustrated though as I want it to go quicker, but I've read enough to know that's not going to happen. 

I really feel like we could do with getting professional help again, but she really doesn't want to.  I don't want to push her on that, especially when she is making an effort, but I'm scared that we might not be able to deal with this without, and I don't want things to ever get to the point where I am just so miserable that I can't stay with her.  I want to spend the rest of my life with her and I don't know whether I should put my foot down again about seeing someone for professional help.  I don't know how fast I can expect her to go or how far.  I know that neurology is the limiting factor and I'm trying to compromise as much as I can, but I feel like my neurology is also limiting in terms of me being unable to accept having practically no reassurance about how she feels about me and physical affection etc. I'm also encouraged by the fact that she does seem to enjoy things that she seemed repulsed by originally, so I know that some change is possible.  

I'd rather not hear stories from people who it hasn't worked out for, unless you can tell me what you'd have done differently.  I'm looking for hope and encouragement, and maybe a little advice if you have had some success with these problems.  

Many thanks (especially if you've read this far!)