After 25 years...

My parents are in the final stages of finalizing their divorce after almost 25 years of marriage and I have no idea how to cope. For starters, my mom never told me why she was leaving my dad and I doubt she'll ever tell me why and that's probably why it's so hard to accept it. It's also starting to affect my outlook on relationships because I'll picture myself in a relationship/marriage, I always think "Oh, well what if we end up breaking up/divorcing?" and I know that that is a 100% toxic thinking process. I'm also worried I'm starting to become a commitment-phobe which I don't want to happen because I want to get married and have a family someday. Because of the divorce, I developed a shopping addiction and then when I turned 21, I started drinking heavily almost every night. I've tried finding articles and self-help books on divorce, but they're all mostly written for little kids. I understand that divorces can be hard for children, but they're also harder for adults. I don't know what to do to cope. I don't like talking about it because it makes me really sad and upset, which is stupid because I do have friends who care about me and love me. My mom and sister moved away and I stayed with my dad so I could finish school and also so he wouldn't be alone, which also makes me a commitment-phobe because the thought of me getting married and leaving my dad by himself scares me. I'm not sure what I can do or what to do.