Loops are funny because there are so many causes.... well, not funny to the user watching it going on.
Anyway, how about starting over? It's a pretty straightforward process.. make sure there is enough battery.. I'd charge it all the way up before starting.
I found that after a few false starts on rooting the very first time, it was best to just go real REAL slowly through the steps in a "dry run" prior to actually getting going on it.. patience.