For what it's worth I don't think you're a fraud. Things go up and down - in fact it's sometimes better to meet with someone when you're feeling better because when you're feeling better you can think more clearly. Which means you can better describe what you have been feeling, whats going on, etc. I've found one thing that's difficult about depression is it's fully possible to feel so horrible you can't get out of bed - literally - one day, and a day or week later you're walking around. When you're walking around it seems silly, stupid even. But it happened. And it matters.

Best of luck with the appointment