Should I go or should I stay?

I am Junior councilor-ing at hoby metro (leadership thing for teens). The thing is the seminar is smack in the middle of my finals. If I go I run the risk of failing two of my hardest regents because ill be gone the weekend before, but if I don't go i lose the valuable college kiss up points which I may need. On top of all this I have a ex-friend who is probably going who is quite pissed off at me and none of my other friends are going. PLUS to get into the seminar I needed 100 hours of community service. My entire family says I should go but I scared. ADVICE!