What's happening on ''learn use photoshop''?

Hi there again!
I made this change up with masks and layers! Oh believe me that was hard thought teacher made it look very easy! x'D The idea of the ''Before'' picture WAS to have horrible much different colored with different kind of lights(flash,lamps,nature light etc.) and then change them from raw ( crude picture, like film ). We have here many little exercises to do now and I've done two.. the other one I've made now was ''suprise'' named picture, where is suppose to put many different pictures with layers to one layer and use some masks. I had only one picture of my own there and it took a long time to make the picture wholy, there were 10 different layers and there came some kind of error and now it's not working. I told to teacher a second ago about it and he was appalled!! So was I, I was so proud of the picture! Seems just that I have to do it all over again to pass the whole program of these lessons.. isn't it sucky?.. I have still 2 things to do ahead and I only have 30 minutes left....