You’re not alone, ED! Many have grappled with this topic. Even at this point in my own journey, I must confess I do not love Mary with the abandon that I wish I could.
From a straight reading of the text in John 19, you wouldn’t necessarily walk away equating every believer with the Blessed Disciple. This is a wonderful analogy and pious meditation, and the faithful need look no further. Common sots like me have to approach Mary’s motherhood from some different directions.
First is the constant teaching and practice of the faithful toward Mary throughout the ages. Mary is seen as the “New Eve.” Insofar as Eve was “Mother of All the Living” after the natural order, so Mary is, by extension, Mother of all those made alive in Her Son, Jesus Christ. If we are “joint heirs with Christ” as in Romans 8:17, it stands to reason that amongst the treasure that is our collective birthright is a common parentage; God our Father and the gift that is the Mother of the Redeemer, made our own Mother.
St. Paul tells young Timothy to “[Entreat] Old women, as mothers: young women, as sisters, in all chastity.” (I Tim 5:2) Which august Lady in the faith might we be most especially directed to treat thusly? While I am exceedingly fond of many of our “elder sisters”, one alone springs to mind as being made worthy to bear the universal title of Mother of the Church. She who by her fiat in the fullness of time gave form and substance to He who is both eternal and infinite.
There’s much more, but that gets us started. Thank you so much for asking!