Guilt over death of husband

My husband died from alcohol (cirrhosis). Over the years we had arguments that I now go back to in my memories and wish I had better responses. I feel that our relationship was part of the reason for his drinking and I feel that if I had had the knowledge that I have now I could have helped him and maybe he would still be here. How do I make a bridge ladder, to cross to become ok with the fact that I can not fix the past?