Hi S. Jones,
You truly have been through a lot already. As Joanna mentioned - find out if chemo or an alternative to radiation therapy would be an option for you. Some things you may want to ask about this surgery is how it will effect:
*eating/swallowing
*speech
*overall quality of life.
You may also want to find out about the risks involved, length of recovery time, therapy that may be involved afterwards and even any questions on swelling and pain. Ask anything and everything you can think of. There are no wrong questions to ask - and the more you are prepared, the better. It's a good idea to list all questions on a piece of paper/notebook - since it's so easy to forget to ask crucial questions as surgery time arrives.
As far as your dad - I truly feel for him. As a caregiver myself - I know the frustration and anguish he must be feeling. Tell him he is not alone - and that there are many people here in this forum who have gone through hellish ordeals and are alive and well, and here to tell about it! There are many caregivers here as well - and if he is able to - he can log on, and we're here to offer support and helpful advice. My thoughts and prayers are with you on your upcoming surgery. I know you will do just fine! God bless and take care. Write again when you can.