[ Singles & Dating ] Open Question : I MADE A HUGE MISTAKE AND I DON'T KNOW WHAT TO DO!?

Ok, so this guy asked me out last night, and I said yes. The problem is I don't want to go out with him. I have way too much to think about and I really don't want to be in a relationship right now. I don't want to hurt him and tell him that I made a mistake, since I already hurt him when he asked me to the homecoming dance last year. I don't know what to do right now. I REALLY don't want a boyfriend at all right now, I have no free-time and I wouldn't be able to see him much outside school. How can I let him go without hurting him terribly?