Did my DA try hard enough?

I agree that your ex is definitely insecure but probably FA not DA, and that the main takeaway here is the very difficult lesson you already learned: you can't date potential or hope for someone to make big changes. That's what dating is about, taking enough time to observe someone's pattern of behaviors and levels of consistency and showing up. When dating someone with an insecure attachment style, those insecurities may not obviously pop up for 1 - 2 years, though after you go through the experience you can usually identify red flags much earlier than that. If you don't have lots of insecure dynamics in your family and you've never dated someone with an insecure attachment style before, it can be very puzzling and take a long time to see and figure out because it's such a different frame of reference. Thought patterns and nervous system conditioning are different between insecure and secure attachers, and expecting their behaviors, motivations, and responses to be like your own if you have a different style doesn't work. That doesn't mean insecure attachers didn't try their best, but it may mean their capacity and definition of "best" is quite different from yours and totally incompatible. Though these issues are often not conscious and rarely intentional if you're not dealing with a personality disorder or other comorbid mental issues. If those more severe issues aren't present, it still doesn't make it a good match or healthy, functional relationship, though.

I've been in similar situations to yours, with multiple FA partners, and I personally overstayed and wasted my own time for years multiple times because I was AP. A big reason I was able to finally overcome that my own attachment style issues was because I want to have kids and am also pushing it on being out of time, and because I'd already spent so many years banging my head against the relationship wall that I'd finally figured out how to identify the real problems and deeply wanted to change and stop being in so much pain (I kept choosing avoidant partners who couldn't follow through on serious relationships, and the reasons I made those decisions were complicated and often ignorant but still wholly on me). It took me a couple years to work out my issues once I focused on it, and AP is slightly less complex to work out than FA because I need to heal the anxious side, not both the anxious and avoidant side. So him being in his mid 40s with a few months of therapy under his belt and no where near taking ownership of his trauma and growing past it into an emotionally mature adult is unfortunately not unusual in a circumstance like this, isn't your fault, and has little to do with you. You didn't cause it, and you gave him benefit of the doubt on his follow through because you didn't know these vastly different mindsets exist. Again, they're complicated defense systems that let children survive trauma (in this, case, mostly likely so he could stay attached to his mom when still a defenseless kid) that can stunt emotional processing and don't serve adult relationships well. Humans naturally grow into them but not out of them, and it takes conscious and very difficult work that he doesn't sound ready to do.

I empathize about fears around missing a limited window to have children, and I'm guessing there's a lot of anger at both him and yourself around that if it's something you wanted. If so, definitely be kind to yourself in that space and make sure you take some time to process and mourn. And don't let getting caught up in what he did detract from doing that. I think it's really important for people to learn about attachment theory and dynamics between styles, but if the focus stays on him it can also be a way to avoid feeling all that and figuring out a new direction for yourself.

I also agree with the advice to block him and keep him out of your life going forward. FA is the come-here-too-close-go-away-too-far-come-back style, due to chaotic and sometimes scary households growing up. As someone with an AP style, I stayed in those "downgraded" situations with my FA exes who wanted to stay best friends but no physical intimacy and no labeled commitment after we broke up. Of course this was confusing, it was like these specific exes tried to split apart emotional intimacy from physical intimacy and compartmentalize them, and what men use you for emotional intimacy but not physical?? I thought for a long time it was unresolved feelings of love and they'd come around, but no. It's part of the predictable pattern and you can indeed stay in limbo indefinitely -- or until you establish strong, healthy boundaries and remove yourself from the roller coaster merry-go-round. And you stick to them strictly, because insecure attachers have a lot of issues with boundaries and you can't put the onus on the other person to act in a way to meet your needs on that. Especially an unaware FA (also called disorganized attachment because they have no organized strategy for getting their own needs met, so forget about trying to meet the needs of another person if they can't handle their own!).

I'm sorry you're going through this. It's going to be a bumpy road to get over it, but you're not alone in your experience.

Alexandra- your response really resonated with me! thank you for sharing. my experience feels so similar to yours. I was LOLing about what you said about what man wants to use you for emotional intimacy but not sex. I think he definitely compartmentalizes sex- its either casual flings w sex or a real relationship with none. Anyway, at first I was fantasizing about him coming back to me, but changed. haha. That's like wishing for a different person basically. To your point, he is mid 40s and not ready to take ownership of his trauma. Also, when you said insecurities may not pop up for 1-2 years, yes! the first year was pretty good- and then Covid hit in our second year, so it was a huge distraction from our issues. I am trying to take that all into consideration, and framing it in my head as, well, at least I had a bud to hang out with during lock down. And at least I am gaining huge insight that can help my future relationships. Thank you again!