I was having the same sort of difficulty with French. On vacation, I realized my ability to speak fluently had vanished over a decade of non-use of the language

I was having the same sort of difficulty with French. On vacation, I realized my ability to speak fluently had vanished over a decade of non-use of the language. I bought a few magazines, then a fiction book, and it's done wonders. It's much more interesting to read about something that I'm interested in than it is to go through exercises. Since what you lose over time is mostly vocabulary, reading is an efficient way to re-grok a language. You just have to get over the initial bump, where you're reading really slow because you stop frequently on unknown words.