Divorce Support Forums: Wife walking away

After 20 years of marriage my wife is leaving me. We have three boys ages 20,18, and 11. It was a shock to me when she told me and she seemed shocked that I was shocked. She has had a bad couple of years. About 10 years into our marriage she went back to school and became a nurse. After finishing nursing school and about one year into first job due to back pain she became addicted to prescription pain killers. She was fired from her first job. Then lost her next job for the same reason. Her nursing liscense were suspended and and she entered a rehab program and has done well and has been clean for a year. She has her liscense back but must be drug tested for 5 years as a condition. She lost her dad about six months ago. Through this I felt I was supportive but looking back probably not as much as I should have been. I really want this marriage to work and am concerned for what it will do to our children. This will also place a huge strain on our finances. We barley make it as it is and she wants to start a new houshold. The last year she worked, picked up our youngest from school, and slept. I did all the laundry and cleaning and my mother who lives with us done all of the cooking. Will any of this info matter in divorce/custody matters.