Codependency Support Group
Codependency is defined as someone who exhibits too much, and often inappropriate, caring for another person's struggles. A codependent person may try to change, or feel shame about their most private thoughts and feelings if they conflict with the other person's struggles. If you are on a journey towards self-love, this support group is for you. Join us and find others...
Some abuser or abusive relationship (like with parents) will create the codependency but we are not codependent with the abuser(s).
The problems of codependency are totally inside of our own mentality, inside our own heart and soul, and the only cure is inside of our self too.
So your codependency did not start all over again with that old BF, because you just need to heal your self.
Even if you go find some new BF who is healthy and well then you will still have the codependency attached to your self and that has nothing to do with the other people.
This link below has a twist to the definition of codependency and it works for me:
http://independentfew.wordpress.com/2014/10/13/codependency-definition/
And having the codependency in your self does not mean that now you have to beat up on your self - no - it means that now you need to start being considerate and respectful of your self, and give your self a long over due break.
TThe way you describe jumping back into relationship with the old bf sounds very much like you are codepdency on him.
Good luck