It's good that you've managed to get an appointment with the psych sooner, have you met them before? I think it would be worth going to the appointment to save you from having to wait longer, maybe just mention to the psych that you want to be as well as possible over Christmas and see what they suggest.
I can understand how hard it is when you've had regular support and then it is reduced quite a bit. When she gets to know you better she should be more understanding of your needs and what support is right for you. What is your support from the support workers going to be like over the Christmas period?