I'm not graduating.

I'm a senior in college and I recently found out that I won't be graduating in May because I have two more classes to take for my minor. I told my boyfriend a while back that I'll be graduating in may and every since then he has been so excited for me. I don't want to disappoint him at all because I've disappointed myself so much already. I don't want him to think I'm a failure. We had our lives planned out around my graduation and now it's all gong to be changed. I'm so disappointed in myself right now and graduation is next week. I have to tell him soon. What would you do and how would you go about telling him?