Couple of thoughts - lots of people fail their skills test first time round - that doesn't mean they are crap pilots - just that they need to work on something - most work on that something and go back and pass.
Second - don't be in a rush to lose your instructor, especially if there are things you need to brush up on. You mention something else in your post "it was quite bumpy this morning". Think about the instructors view - he/she needs to be 100% confident that you have everything lined up for a successful first solo - that's a lot of weight on their shoulders as well as yours.
I expect "quite bumpy" and some rudder practice, just tipped the balance. Go practice, go solo, do your exams, XC, skills test and enjoy
