Finally have some of my brain back.
I'm just going to riff a little here, and hopefully some of it will be helpful to you.
Some of my stuff around this is pretty similar to some of your stuff. I also had abuse normalized for me for a while there, and part of that situation, oddly enough, was because one of my parents grew up a lot like you (the Irish one, no less, thus part of why I so get some of the cultural issues you've been immersed in and have been negatively impacted by), and I think your bits with leaving, and what makes it hard, were also her bits with leaving. For me, some other things that came from abuse, dysfunction, or both, is that I have a very hard time seeing narcissism. That way of behaving was very, very normalized for me, as I was surround by it intensely, and so I will often end up with narcissistic people, or get drawn into their stuff and by the time I see it, I'm usually in pretty deep. I also have tended to respond to that kind of behaviour in ways that haven't been healthy for me.
I, too, tend to think the best of people: I take people at their word, very literally, and don't tend to look between the lines because it just doesn't feel like something one has to do. So I also get being gullible in that way.
The leaving bits aren't my personal challenges: by and large, I'm actually pretty good at leaving. In shelter settings with teens, those who run away from home or foster care or shelters are often labeled "runners," and that's something that has often fit me, too: I'd be labeled a runner as well (and was one when I was a teen, though, as is often the case with the teens in those settings labeled that way, I ran to survive and it's very good that I did, as -- IMO -- it often is that they do).
I think, for me, some of breaking my own patterns with abusive people was helped by my being forced to survive, in a word. There was a point, in my teens, where my life was at risk in some ways, pretty literally, and my sense of self was absolutely at risk, so it was basically give up and give in -- and lose myself as a self -- or get out. Get out was where I went, and while that also cost me in a lot of ways, that way of standing up for myself made starting to work through all of this a lot easier, I think. You're not in that same kind of place, but it sounds like with this last relationship, you might have been in something similar, and the way you're really fighting for yourself now feels, to me, like that kind of strength and drive I felt after having made my choices way back when, if that makes sense. It's a good place to be in, in my experience, even though there is that thing where you come out, and then you're sitting there with these big heavy bags to lug around until you can find a way and a place to unpack them, and when you're still so tired from being worn down for so long, no less.
I know for me that a few things have really helped over the decades that I think might help you, too:
• Being on my own and being autonomous and independent. It's much harder to be afraid of being alone when you just take a leap and do it. Live alone, if you can. Even when living alone for me meant incredibly precarious financial situations, as if often did, I think the pros outweighed the cons, by a serious long shot. Don't commit to serious romantic relationships for a while: play the field, and hold yourself to that more easily by telling anyone you start seeing upfront that you're not in a place to do more than something casual (that can be about sex, but it doesn't have to be, or doesn't have to be just about sex: it can also just be about keeping dating AT dating). Make what committed relationships you have be friends and communities, rather than romantic or sexual relationships.
• Do what you can to care less about what someone else might think of you. I know it's super-hard, especially with the setups you've had around this, to accept that what you do actually can't control what others think of you, but it can't. Even if you stay with someone awful, people STILL might think you're a bitch, for instance, or stuck up, or whatever. Try and remind yourself that if you lead with what YOU think of you, and let that be the most important thing, then a) if people don't like you, well people just don't like you, because you're being you, and that's going to happen. We all have people we don't like, and the why of that is all over the place: sometimes it's because someone is an asshole, sometimes it's because we're jealous, sometimes it's because someone reminds us of parts of ourselves we don't like, and sometimes we just misunderstand someone. But if YOU like you, it's a lot harder to stay focused on trying to act in a way that controls what others may think, and when others think poorly of you, it's a lot harder for that to be something that hits you very hard. I know for me that getting there, through all of my life, has been helped a lot by simply doing things with my life that *I* find great value in, that *I* think are important, and that make me feel good about myself, even when in some way I fail at those things, or don't do them as well as I'd like to.
• Take some baby steps to take risks with saying no. This is another thing where I think you just have to leap, and breathe your way through it, even when your heart is racing. Try doing it in less-loaded places first -- like some dude trying to get your attention at the pub when you don't want to give it, for instance.
• If you can find a good therapist, go all in. I lucked out with that during some of my hardest times in life, including one therapist who was even willing to waive their fees for me, bless her heart. But if and when you can't find that, or have to wait for that, see what you can do to DIY it. Self-help books that are good can be everything (still going to make you a little list this week around assertiveness stuff and the curse of "nice"). Building a support group for yourself of friends with similar stuff, or who can at least listen to you and support you, even if your issues and their issues aren't the same. Journaling can be another giant help, or creative pursuits: I know making music and visual art have both been ways I have worked through some of my hardest stuff. Time all alone that's extended and truly alone is another help in my experience, like a solo camping weekend, where it's just you, your heart and head, and the forest. I find for myself -- and you may or may not feel the same or experience this yourself -- that doing what I can to just let myself go to my darkest, scariest places and explore them without fighting my hard feelings or trying to avoid them really benefits me.
That's a lot of riff there, and sorry that it's so disjointed. I hope at least some of it is of some value to you, but if not, you're certainly welcome to steer me in another direction, and by all means, we can keep talking if you'd like.