I'm very surprised at the number of hours you've flown without going solo.
I did it at about hour 15 I think, and I'm aware others will do it in less than 10.
This post isn't to question your ability, it's to question the syllabus - I presumed it was standard, and that each student worked through the same lessons in order meaning you'd get to lesson X "solo circuit" and fly it once the instructor thought you ready?
Can instructors mix and match the lesson order?