I feel ya. Fearful-avoidant here too. Meet person->attach->fear->disconnect cycle over and over and over. I don't have any advice on parenting or something that will solidly work for you, but I do find things are less chaotic when there is a bit of distance between others and myself.

I would say a good first step is to gain some insight and awareness of when and how the insecure attachment is affecting you. In therapy I've been working on behavioral chain analyses (more for BPD impulsivity but I think most people w/BPD have either an anxious-preoccupied or fearful-avoidant style, and those without BPD could probably use it looking at regretted actions within a relationship). Basically you look back at something you wish you didn't do and identify vulnerabilities, triggering factors, the behavior itself, short-term and long-term affects along with ways to change the behavior next time. I can see how that would be helpful with some fearful-avoidant behaviors in relationships (i.e. did x because of feeling overly affectionate or y because of wanting to distance self..and then trying to balance the extremes trying to integrate reason mind with emotion mind).

Fearful-avoidant feels a lot to me like black and white (probably subconscious) thinking leading to alternating between extreme, opposite emotions and behaviors within relationships. If you can actively challenge the intense close-ness and the alternating fear of such intimacy, over time it'll become more engrained and automatic.

Just some ideas. There's probably some better literature out there on working your way towards secure attachment and dealing with things during that process.