It's your progress that really matters here -- if you're doing what you need to feel safe (without causing harm to someone else), then I say go with it – FOR NOW. It's obvious from what you write that you already know that there's something not quite correct about how you're dealing with this issue, so it is a bit like a game, isn't it, then? At some point you'll probably be ready and willing to let go of THAT, as well.
For me, I find that acceptance is like an onion with infinite layers: once I think that I've finally accepted everything I inevitably find that there's yet another level beneath, with different issues that reveal different aspects of what acceptance really means. I imagine that once you pass through this phase, you'll accept what you need to in terms of your limitations, as well as your boyfriend's, and begin to feel safe without the need to blame him.
However, I think that looking at this as a lose-lose situation might keep you stuck in thinking about your ex as someone you COULD HAVE helped (or saved), if only the playing field had been more even, or if it hadn't rained, etc. (to maintain the gaming metaphor). In my opinion, thinking like we lost keeps us stuck; I rather prefer to focus on who I am and what I will become – that's my only responsibility. No one else can do it for me, and I am not responsible for what someone else will become.... believe me, I still have hard moments (I'm 7 months since breaking contact with my ex), but if I look back on how I was living, how miserable and really screwed up I was, I know that this is the best path for me.