I believe every blue belt has experienced this. You have been training for a year or so and have improved a lot, but suddenly you feel that your progress has stopped. Many people think about quitting around this time and for this reason. While learning martial arts there will always be learning curbs, you just need to know that part of learning martial arts is learning patients and discipline. If you make it through a hard time like this then you have just overcome one of the biggest obstacles you will face in the process of learning your martial art.