It sounds to me like you're absolutely normal!! You don't just put the white coat and stethescope, and bingo, you're a pro! How did you feel the first time you interviewed some hot shot?
I'm proud of you for making such a major change in careers! I think you're going to be great!
What are you supposed to be getting out of this experience? Like, what do the objectives say? If communication skills are the primary objective, start with small talk. If the patient is willing to share, ask them what they did before. Compliment them. Use touch carefully, but it can create some communication of it's own, esp if they can't talk well. Body language is VERY important, try not to cross arms and legs, and lean forward. Grooming is good. What woman doesn't like some hand cream massaged into her hands--but watch out for that arthritis! Ask first of course. Some older patients DON't like to be called by their first names, they are Mr/Mrs, and watch out for the "honeys" and "dears". If they have pictures, comment on those.
Try to forget about what you're wearing--focus on the client. One good thing about our funky student nurse uniforms in days of yore was that we didn't have to pretend we were something we weren't--one glance and the clients KNEW we were students!!
Practice with your classmates or friends -- at first, some of the things the instructors tell you to say sound weird, but, after a while, it'll work. If you really hate it, make up something of your own. In your former life, you had tricks to help people open up if they got suddenly shy on air--use 'em.
Older people are walking, ok maybe rolling, oral historians. The men may be more willing to talk about events, the women, their families.
Keep in touch, we'll be more than willing to let you whine/vent, etc. There's umpty thousand people on this board, and we're all rooting for you!