I had the opposite problem. I had no notion of an ‘ideal’ mother because I’d never seen one. I let my son know and witness too much of the true me when I was very unstable. One night I tried to overdose by taking a lot of prescription medications; I stuck my finger down my throat when I realized that as fucked-up as I was, I was the best person to parent him. From that moment, I worked to become a true role-model of the kind of person I hope my son will become.
At some point long before that, I’d also had the clarity of mind to realize that the ultimate goal of parenting was to let go; and that it was best for both of us if I do it gradually, rather than to coddle him all along then expect him to turn a certain age and be a “grown-up” the way I saw others do it. I worked to give him increasingly more responsibility as he showed the ability to take it on.
When he was 14 and about to start High School, I wrote him a note explaining that I knew that I could no longer tell him what to do; and that I will continue to give him my opinions and guidance, but that he must make his own choices and deal with the consequences. He’ll be 22 soon, and we have a good relationship.
Perhaps try writing your son a farewell note – something you might give to him when or after you depart. Take some time writing and editing it. First drafts should flow freely, purging all the emotions you feel, and trying your best to explain why you made the choices you did, and coming back to the point that your choices were made out of love and wanting the best for him. Wrap up the letter with a statement of what you wish for him and how you hope to see the relationship between you evolve as you have physical distance and as both of you get older. Then edit and rework the phrasing to convey these thoughts and feelings so that he might relate to your position as well as possible. In the long run, you might decide not to give him the note, but the process of purging and rephrasing will still benefit you in communicating with him during this transition.
I am glad to learn that he has sought help and is receiving treatment.