refusal to take formula

Brandon was getting half of his daily intake through formula and the rest with breast.  But now we are 25% breast and 75% breast  because towards the end of the day he's just irritated by his teething and cranky because it's getting close to bedtime.  Needless to say I'm exhausted.  He still won't let Paul put him to bed.  I'm a bit worried about this because Saturday night I'm going to be in Amsterdam for a concert.  I pray Brandon will be good for Daddy, but I guess I'll find out how that works out when I get home Saturday night.