That is indeed unfortunate. I think it was wrong of the interviewer to hint that you had the job, when there was not a job offer being made. I can understand why you would feel baffled and upset. You might also be feeling angry and betrayed. But please don't stake your whole future as a nurse on this one interview or job opening. Until the offer is made, there are so many things that can happen. There are lots of nurses vying for jobs and the competition is pretty intense. Who knows, the boss's cousin's daughter might have just called her to ask for an interview as you were walking out of the office. I hate to think that, but anything can happen until you've got the offer in hand.
I have found some interviewing and job search
books at the library with really good advice about how to "close the offer" in the interview. Supposedly there is a point at which, if the interviewer is hinting around, that you can say something like, "it sounds like you might be ready to offer me the job and if that is the case, I'm ready to accept." I'm not at all sure this is how it was described, but you get the idea. There are techniques that salespeople use to "close the deal." I ought to look that up myself, since I will, hopefully, be having some interviews soon.
As others have told me recently, there are many opportunities out there. I know what it feels like to be discouraged by a setback and to feel like chucking the whole business. Thankfully that feeling has lessened and I'm ready to get back up on that horse that threw me! I hope you will, too. A bit bruised, but a whole lot wiser! Good luck!