I think you are probably onto something, there. Many psychologists believe we bring other people into our lives hoping to have a "re-do" to heal wounds from childhood. I don't know that that explains every problem people have in relationships, but it intuitively makes sense in many situations.
It really MIGHT be that simple, but just as self-knowledge doesn't "fix" alcoholism, having that knowledge won't, in and of itself, fix your problems. Still, it gives you and your therapist something to work from.
I really admire the hard work you are putting into this--you'll get where you want to be eventually, I have no doubt!