A new goal

I think I may have decided what I want to do in life. I feel like I really want to get my Ph.D. in history and become a college professor. Part of me really feels like it is too much, like I am just bound to fail. However, another part tells me that it is wrong to waste your passion just because you feel that you can't succeed. I also might like to work with charities, I know they will take a history degree. Any thoughts?