Hello lygod43,
I think anyone would be frightened, regardless of how innocent they know themselves to be.
For what it is worth, try not to worry too much. Make a recording of the call, since your emotions will almost certainly block a lot of what they say, and possibly what you say. They may ask you for evidence of something, in which case you need to take that seriously and get it if you can, or tell them why not if you can't. You may well be given deadlines to do something by - if you can't keep that deadline communicate. I have never known them refuse a reasonable extension.
I hope it goes smoothly for you,
Catherine
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
