What did you do to get this "good period" ? Nothing. What did you do to lose this "good period" ? Nothing. We all have up periods and down periods with our fluency. I dont think anyone really knows what makes them happen. While most periods aren't as stark as yours, most of us get them and lose them. I wouldn't obsess too much on how to get it again and keep it. I'd just enjoy it when it comes and bear it when it goes the other way. As they say, easy come, easy go.