Hi Mayo,
What a shock that must have been for you to find out that way. It would have felt surreal for quite awhile!
Did the gynaecologist suggest anything to help the narrowed vagina such as further surgery or using dilators? If you are in the USA/Canada region it could be good to contact the CARES Foundation (top right corner of this page, scroll back) to ask whether you could be put in contact with a gynaecologist/surgeon who has done a lot of surgery reconstructions on CAH girls to get another opinion; that is if you are unhappy with how things are.
I know you are not very old therefore it is sad that some parents in this day and age are still finding it hard to discuss these issues with their daughters/children. I'm sure it must have worried your mother that she never did tell you - do you think?
My parents were never very forthcoming with information about CAH either and my sister and I were kept in the dark. For some parents it's to do with being very embarrased and not knowing what to say. For some it's different cultural perspectives, for some it's just not knowing much themselves. I think the lack of knowledge about this condition should be no excuse for the next generation of parents as the internet is saturated with info.
Remember knowledge is power and I commend you for learning as much as you can about this condition. Someday I'm sure, that out of this horrible experience you be strengthened and will be able to help others who maybe have gone through a similar thing.