Yes, it happens, probably happened to all of us!
What happens is that you get a few things wrong, and it disturbs your flow, you anticipate less, things build up, you get more pressured and the situation gets worse. It's also refered to as letting the aeroplane get ahead of you.
The only way to tackle it is to cure that overload. Someone mentioned asking the instructor to handle the R/t. Excellent idea. Hand a few things off for as long as it takes to get back on track. I'd even go so far as to say there's a point you should discontinue the lesson.
Same thing may happen to you even after the PPL - again you have to manage/correct/reset and not press on into a worsening situation. Slow down, orbiting for a while, or even land somewhere, whatever works.
Right now.. don't worry. It's all part of the process.