I did my first solo last September. Like you I was worried about the landing.
My instructor had mentioned a few minor points on the previous circuits, and I didn't have a single faultless one, so I was very surprised when she opened the door to get out and said 'one on your own then?'
I missed the line in my check-list about flaps, so did my first flapless take-off, realised when I went to retract them! The height was all over the place due to the change of weight, and on nervous finals ATC asked if it was going to be a full stop or not. My reply was along the lines of 'I hope so!'.
The landing was fine and the sense of relief and achievement is something I'll never forget. Easily the best day in my flying training.
I went on to do my QXC in December and my GST at the end of January, and passed.
As everyone else said above - your instructor knows your ability better than you do.