(((((((((((((( maximumeffect )))))))))))))))))))))

Talking to a teacher may help ease your mind or maybe they can help you make other arrangements. I am sure if your counselor has arranged for this person to pick you up then they probably can be trusted, some mental health centers actually hire people to pick clients up when they need a ride.
I am not sure what your meeting may be about, it must be very stressful not knowing what is going to happen and why you have this meeting but try to relax. Good luck tomorrow.