For what it's worth I agree with some of the replies already posted. I reached a plateau and 'almost' went solo at 16 hours! It was 23 before I eventually did.
I remember that Saturday morning as if it was yesterday (1995) - my usual instructor couldn't take my up as he was doing a flight test so I went up with another instructor, who I knew well enough but had never flown with. He made me look at the full picture in a slightly different way - we did three circuits and then he got out and just said 'ok just go and do that again!' I had got bogged down with the detail of what I was seeing and looking for - look at the whole picture.
Good luck and be ready for a much faster climb when that right hand seat is empty:-)