Suspect ADHD is destrying my marriage

My spouses family has generations of depression, alcoholism and suicide, we have argued for years about responsibilities and poor financial decisions. Recently I was made aware of Adult ADHD. My marriage is in trouble. My wife resents the issues we have had through our marriage and is contemplating divorce. As this is happening I am trying to get my son tested for the issues he has that appear to be ADHD, he is 2o yrs old. So much time has passed that these issues were not recognized, I now see what communication problems and misunderstandings of intention plagued or marriage, but my wife who shows so many of the signs takes offense to me suggesting it could be an issue. My children who also in retrospect have had all these symptoms that I recently became aware need to be my priority. I do not want to lose my marriage, but how can I communicate this with a wife who is angry and full of resentment over the suspected ADHD misunderstandings in our marriage. This is a very painful stage to go through.