My Son in Prison

My son who is 30 years old now. Was sent to prison. He did something so stupid that words can't even begin to explain. I'm so mad and upset that I just don't know what to do. I'm the only one who is having anything to do with him. Everyone else has abandon him. I feel guilt when I don't have time to write but when I read his letters i get so sad. His life is ruined. And I can't do anything to fix it. Whats worst is he doesn't see that. I guess that for the best he might give up if he did. How do you cope with this pain ? I keep wondering did I fail him some how. Please tell me how some of you deal with it