I'm sure the doctors there have seen similar cases to yours and will be able to help you work all these things out and make you as comfortable as possible. They can give you better answers once they see you and get a detailed history.
I know it's scary (not knowing what to expect), but I think you're making a great decision by going to inpatient. Having gone that route myself, I have to say it was one of the best things I ever did for myself.
Hang in there and try not to worry too much.....
