Forever----I can remember some of the material about children and divorce from my developmental psychology classes.......
While they didn't deny that it is a significant event in the lives---the point was made that it didn't automatically mean that it was always a crippling effect on their lives.
Many research results were cited---scientific research....
The very MAIN point that I remember is this------that, on average, the adjustments to the new divorced situation was stabilized at about 2 years, after the actual divorce. This was true for both the spouses and the children.
That the problem was not so much the actual Divorce---but, HOW the divorce was handled after the fact. How civilized the parents were toward each other---without arguing and back biting was the most important factor, here. That, living in a home with a bad and contentious marriage was worse for children than going through a civilized divorce where children were still nourished and loved.
I get it that you feel sick about the advent of divorce---but, that boat has already sailed, hasn't it? This,of course, will be your own personal challenge to process. I think you will get past it. Wallowing in personal guilt will not add one molecule of any good for you---in fact, false guilt will be destructive to your progress and peace of mind. A mother with peace of mind is the best gift to a child. They take their security and cues about life from you.
Forever---if you are truly interested in what the scientific research has to say, from the field of psychology----I suggest this. Go to the TEXTBOOK section of amazon.com. Get a book in the Developmental Psychology section---the kind that is taught in colleges and universities. Read the sections that address divorce. Also, the textbooks on marriage and family \ go into the effect of divorce and family trauma situations on children. (textbooks tend to be pricey--but, you can get greatly reduced prices on the Used books).
I think they are worth studying. lol---I took these courses after my own kids were long grown up! It would have been great if I had known about them when my kids were still little. Oh, well.