I too am very new to CR and have only done it once or twice. So far it has not been so long that I haven't been able to handle it. I have also been lucky that I have not been teasted too much during my CR yet, but I know that will come with time!
I agree that if it I came outside of Master teasing me, and it was a conscious thought, that would deserve a serious punishment. If I came during a time when he was teasing me and making me edge, I would hope he would see that I had really tried hard not to cum. I am fortunate in that I have grown used to edging and somehow seem to be able to hold off cumming for quite a while, but that doesn't mean I would't crack one day either.
I do think in all this, the human side has to be considered. As Ruby said, not everyone is suited to CR and in the end, you want it to be an activity that strengthens your relationship and/ or that you learn and grow from. I am glad that your Master didn't keep you on it for very long at the start. Good luck and continue to have fun exploring.