First of all you are a WSO under training, not a nav any more!!
I suggest you just take things one day at a time, one trip at a time, and try to remain motivated and positive. When I went through nav school (many years ago) lots of guys failed trips. What happened to them subsequently was largely dependent on what their attitude had been throughout the course. The guys with the right attitude got re-flys or re-courses, the guys with the wrong attitude were civilians quite quickly.
I guess what I am trying to say is that in training your approach can be as important as your ability. Instructors will fight hard to help "tryers", and a good plug from one of your instructors at a review board can make all the difference!
Good luck for the future!!