I commend you for being so introspective and think it will serve you well. I avoided some of the shame and embarrassment you refer to, (Jeez! How could I be SO stupid!) by trying to remember that there is a lesson in each experience. And, FWIW, I take great pride in my education and work achievements, but that didn’t stop me from being quite the doormat in this one corner of my life.
In addition to the great resources here regarding relationships affected by addiction, I also found Natalie Lue’s writings helpful. Her books, (including Mr. Unavailable and the Fallback Girl) and resources are more about balance in relationships in general and may be of interest.
-bora