First off, since you aren't having much issues on a day to day basis try to understand what has changed. Maybe you just need more physical exercise, or even different headphones (fun fact, but people perceive their speech differently in different headphones). I had issues with fluency in a foreign language, I just watched TV series with a lot of talking and was repeating after actors. Did wonders at one point, because the brain wasn't that much concerned with what is being said, it was concerned with what's needed to say next.