Forgetting my Japanese

I am seriously forgetting all my Japanese. I speak English at home, I work in an English-only environment now and my last Japanese class was in February before we left Nagoya. It’s a bad situation. My university are offering free classes and I went along for a level check today. The teacher asked me a few questions in Japanese and I thought I muddled through. I always forget numbers and dates, so that didn’t look good (I wanted to tell her that I mix them up in English too half the time). At the end of the interview, she told me that I would be put in the beginner’s class! I was so upset! I’m not a beginner! After 3 years of living in Japan – how can I be put in the beginner’s class!? I knew I was rusty, but things were worse that I imagined! I now know how my students feel when they are placed in low streams at university after years of study. It feels like everything up til now has been a waste of time. Now that I have calmed down a bit, I know this isn’t true and I am determined not to give up.