Welcome to SR......you've stumbled into a forum of people who know exactly what you are going through and the feelings that you are feeling. Every single one of us loves someone who is addicted to drugs. You are not alone.
Staying in the marriage or not is such an individual choice and no one here can tell you what to do. However, we can share what we do to cope with the pain, anxiety, fear, and all of the other emotions that we carry due to our relationship with someone with this disease. The addict in my life is my adult son. He is turning 30 this month.
For me, I found comfort at Naranon and Alanon meetings (I go to one of each every week) and here on SR. It is possible to find peace whether our loved one continues to use or not. I work hard on myself every single day to keep MY head in a good place because that is what I can control.
You, your wife, and your baby daughter will be in my prayers today.
gentle hugs
ke