Quinze, can I ask how many of the hours you have flown are in the circuit? Presumably you've done all the basic handling and emergencies before really circuit bashing, but have you done anything else? Also when you changed schools did they start you from scratch again or try to pick up where you were and continue from that?
There are many factors that can contribute to hours in the sky prior to going solo, for example longish transits to the training area. What kind of place are you flying at? Is it a busy airport or a farm strip?
If you were doing fine until getting into the circuit, I suggest you find a very old and experienced instructor and see where you are really at. I've flown with instructors that flew with me in the circuit and then said that I was getting there, and I think they are time wasters. You need to find an instructor that instructs because they enjoy it, and isn't looking to put hours in his/ her log book.