So I'll try to keep this light on personal details, since I think the broad strokes of my situation are probably relevant and familiar to lots of people who have experienced this pairing...

About 3 weeks ago my Fearful-Avoidant girlfriend broke things off with me. We'd been dating for 2 and a half years. I generally have a fairly secure attachment style, but lean somewhat Anxious-Preoccupied. Over the last 8 or 9 months, however, for various reasons, I became increasingly Anxious in how I related to her. The infographic at the top of this blog post captures pretty much exactly the emotional feedback loop we got caught in.

This was the third time she'd broken up with me since August – both times I'd convinced her to give it another try – but she was adamant that this time was for good. Flash forward to 10 days later and she was reaching out to me asking if I would be open to discussing getting back together. Obviously I was extremely hesitant about this, given so little time had passed, and given her failure to truly commit after our previous reconciliations.

But after speaking on the phone with her, I did get the sense that she'd done a lot of reflection, and that her desire was coming from a place of genuine love, regret, and reasoned consideration, rather than simply missing me or feeling lonely. We discussed attachment styles and were very much on the same page about what went wrong and what we both could have done differently, without blaming one another. We agreed to check in again after a few weeks.

My questions now though are:

1. How do I assess whether this is something I should even be considering? After her repeatedly telling me she would "commit to trying" only to break up with me after a few weeks, I don't trust her when she says she's willing to commit yet again. Without feeling secure that she's not going to just immediately quit again at the first sign of trouble, I feel it won't be possible to work on developing more secure attachment together, since I'll be going into things already feeling Anxious and distrustful. I know I want to see her take concrete actions to demonstrate commitment rather than merely make statements, but aside from her entering therapy (which she's talked about doing the entire time I've known her but has never acted on), I'm not sure what these could be.
2. If we do decide to try again, what sorts of goals, intentions, or rules should we be setting for ourselves and for the relationship? It's a little confusing to me how we should be approaching things: we want to keep things from being too "heavy" and focusing too much on the relationship (and especially to avoid over-analyzing it or focusing on the negative), but we also want to make improving the way we relate to one another something that we consciously work at, and at the same time, we recognize that our history makes this very different from starting a new relationship with a new person. For anyone who's successfully done this: what did you establish at the beginning that was effective at breaking those old patterns or keeping them manageable? The more practical the suggestions the better.

Thank you!