Hi susanw,
At the time of this post, the post would probably be irrelevant to your original intentions, but I post anyway for other purposes.
To your query: This is the main part of learning language... using it! I think a great technique to use that I used for a month while I was staying with a host family in Japan (but this will probably work with your Japanese instructor), is to simply start thinking in Japanese. Whatever you don't know how to say, start learning how to say it. Ask someone who knows and write it down. Learn the sentence structures. Ironically most of this common stuff is not taught in books at beginning intermediate despite them being necessary to expressing important items. This will test not only your Japanese, but your English. Often, native speakers use "complex" metaphoric phrases without knowing so. You need to start thinking simply and in the most basic of English, and slowly you will learn that you know how to say so much! I'm no expert of the language... far from it, but I can say that if you keep working on this and write down new things that you need to learn to express your thoughts, you'll soon realize how much you can speak. But of course, as a student of any language (even many native speakers and their very own language!) there is always so much more to learn.