Dear caroline:
I do not perceive your ex as a bad guy at all and like you asked I will not be judging you. I can relate to your fear of being vulnerable on this forum (to others’ judgments, criticism) as well as being vulnerable with your boyfriend when in a relationship with him. I perceive the two of you as imperfect people. Perfection is not possible though. Regarding your guilt: I struggled with massive amounts of guilt. What finally got through to me and was immensely helpful is this reality:

I am only responsible for my participation in every interaction.

Your ex is responsible, fully responsible, 100% responsible for his participation in the relationship with you, for his choices in the context of your relationship. You didn’t “make him” be in relationship with you. True, you are 100% responsible for your choices and behavior in the relationship but he is responsible for his… which means…

… the nature of the relationship you had with the ex, what it was, how long it was, there is a shared responsiblity of 50-50.

Another point that is extremely helpful to me is self compassion. It took me many years to realize that as a child i was not a bad person. I only believed that I was. I finally realized I was a good child, born good, loving and wanting to be loved. Things went wrong and I isolated and withdrew and distrusted people and of course I was not loving most of the time- I was in a self protection mode. I forgive myself now. I let go of my anger toward myself, my own judgment against myself.

What do you think???
anita