if you need to, tell the prof. that you have a personal matter to deal with...
no one will turn that down.
also, just take a breathe, you are doing the totally correct thing for you. you have a cause and a reason. go to the meeting, find out what you need to do and get it done.
you are a bright, talented woman. this is all quite possible.
do not get scared.
you may just surprise yourself.
good luck!!!
and bravo.
mmcat