You're not being unreasonable...that's just lame. She shouldn't have offered and then yanked the offer back like that (esp. when she knows you are already upset about your b-day, etc.). The best way to handle the situation once she made the offer was to ask that you get back to her with an answer w/in, let's say, 24-48 hours, and then she could fill your timeslot if you decided not to attend your usual appt. But if she was going to so quickly rescind her offer, she never should have offered at all.