Does an interview help for college admissions...?

Are you positive that the last one went that badly? Because unless you spend the whole time talking about how unqualified you are or reveal some major psychological issues or that you know absolutely nothing about the school, it's very difficult for a college interview alone to sink your chances. Not doing one when the school recommends it, on the other hand, sends the message that you're not serious about going there. Besides, you won't be able to avoid interviews in the working world, so now's a good time to get comfortable with them. Do your research, prep some common answers in advance (why this school, what are your interests, etc.) and have some thoughtful questions ready, and you should be okay. Really.