How Can I Turn My Boyfriend's Life Around Before It Is Too Late?

My boyfriend didn't graduated from high school (high school dropout) and I'm trying to convince him that he can go back. He throws all kind of excuses at me. He has elipespy and it is interfering with his knowledge and he feels like he is not smart. He is using his medical disability as a hold in a his life. He is not interested in school and giving himself a second chance. He would rather give his life to the streets (DRUG Dealer). I told him to think about the future especially if he wanted to be with me. I highlighted the facts about how the dealers would put his, mines, and our future children in danger and I'm not having it. I told him by doing it he only has three consequences on which one is good. He could even straighten up, go to jail, or get killed. I told him that I don't want my children to see their father in a casket or behind bars. I will help him and I need some more advice to convince him. HELP ME BEFORE IT IS TOO LATE PLZ.