I, like the rest of the commenter's here, do certainly agree that a break can be all you need. However, I think the OP is missing a valuable lesson, which is that not only should they focus on getting the code to work they need to understand what was wrong and importantly - how to spot the symptoms that it was wrong. In this case, it was a misnamed variable. It's great that that's been fixed, but it's very easy to go hurtling on into the next problem. A few minutes of reading the error message again (and perhaps trying to cause it somewhere else in purpose) goes along way in building up a much more reactive way of working.
Also the process showed him his lack of knowledge very clearly: He can't read error messages. This is an useful skill in every language although it transfers not at all to any other activity (even reading compiler messages of a different vendor). Especially since this was a common error it is important to realize it early and fast. You just can't go to sleep every time you have a typo. OP only sees the immediate solution (insofar just waiting for a flash of genius counts as a solution) but no the actual error.
