Closure is about certainty, not forgiveness. So it seems like you are pretty certain this woman is not good for you, so your continued thinking, stalking, etc. with this woman are not to do with her or your relationship with her. Most likely you are uncertain and unclear about yourself in some way. You have not developed the knowledge and wisdom that would lead you to a better (or good) relationship, so you stay fixated on this horrible relationship because it is safer for you to stay fixated on her than to throw yourself into the deep end on some new horrible woman where you lack the conscious knowledge that she isn't right. That's my theory anyways.
Explore your own self and your family patterns and try to find wisdom there and establish certainty and closure from there.
Again, without closure about yourself, you;re never going to find this great future wife. So current YOU cannot fathom closure about your past behaviours, you still judge yourself on these actions and thus you imagine all other people would be right to as well. And until you gain the wisdom and closure to get past it yourself, other people will see that you are not past it and they will judge you. So that is why you cannot fathom being honest about yourself in the future, because future YOU is the only version of yourself that can even fathom honesty and closure