Thank you for this. Can I just check that it's this book you're both referring to? https://www.amazon.com/Dialectical-Behavior-Therapy-Skills-Workbook/dp/B01FGN7L98/ref=tmm_mmp_swatch_0?_encoding=UTF8&qid=&sr=
I literally just read a book called Living With the Passive-Aggressive Man today that talks about the misplaced aggression they can have as a result of their mother wound. It wasn't the most amazing deep dive and obviously it's gendered, but it does go into the dynamic and offer some recommendations (both tactical and strategic) for dealing with it. It doesn't deal directly with attachment theory, but it makes the point that the generalized passive-aggressive posture is deep down about resenting their own dependency on attachment figures and then projecting that turmoil on to them. In his case it sounds very much like a serious reproduction of his enmeshed upbringing too... but the book makes the point that passive-aggressive people sometimes get a kind of sick (but very subconscious!) satisfaction from being able to "disrupt" others in this way because of how helpless and powerless they feel. Anyway it's a super quick read, may be helpful.
I was doing a general deep dive into passive-aggressiveness last night too and read some of Theodore Millon's Disorders of Personality about the negativistic personality type. I am in no way suggesting that your partner has a personality disorder, but this book does have case examples of passive-aggressive personality types and goes into more clinical detail about the hows and whys of passive-aggressiveness. It also includes therapeutic approaches. I know you are not trying to be his therapist, but I also know you are a fellow nerd who enjoys books about these kinds of things. The specific chapter (11) is called DISCONTENTED STYLES, RESENTFUL TYPES, NEGATIVISTIC DISORDERS: THE DRN SPECTRUM, it may be possible to find the excerpt online, but DM if you want a pdf.
This is the one I used when I did therapy at a facility. There's also one I have for neurodivergent people but I haven't actually looked into it. The one linked is by the creator of DBT and super easy to use on your own.
This is the workbook I used during DBT. It has handouts that explain the skill itself, then worksheets to actually practice. During group we didn't do anything special. We literally read through the handouts together, were assigned homework of the corresponding worksheet, and then talked about the homework as a group the next session. Rinse, repeat.
So it would be super easy to go through on your own.
This book: https://www.amazon.ca/Youre-Office-Its-Already-Late/dp/1250130778
Its called, "If youre in my office, its already too late". Amazing read about what makes relationships fail from the eyes of a divorce lawyer. This book changed my life and the way that I relate to others better than any text I have ever read. Because it plainly laid out what people do and how to correct it.
What I got from it is that it doesn't matter what your attachment style is, you need to pay attention to others and communicate. If you can't do that, you will always fall into problems. I have actually implemented those two things and seen my relationships change drastically.
I'm still avoidant, but a communicative avoidant. Is that a thing? haha
There's a lot going on here, and I love that you are so openly laying it all out for people to help you. People who have avoidant attachment typically have a hard time opening up to people, so I think this is a really great first step! Like others have said, internet strangers are no substitutes for a good therapist. I don't know where you are located, but I would highly urge you to find a trauma therapist who also has training in DBT (dialectical behavior therapy). It sounds like your family of origin issues are replaying themselves in your current family context, and a good therapist can help you break the cycle of intergenerational trauma by building more self awareness and helping you make more conscious choices about how you respond to situations. People with avoidant attachment styles often report having happy childhoods or having few memories of their childhood, when the reality was much different (look up research on the Adult Attachment Interview for more info!). I strongly suspect that your family environment was frightening for you growing up, and there is a lot of healing that needs to happen in order for you to feel safe in your adult world, be able to form deep adult relationships, etc.
There are some workbooks that you might find fun/insightful/helpful:
Transforming the Living Legacy of Trauma
Keep us updated if you have any breakthroughs! I'll be thinking of you. Good luck!