Normal.

"The truth is we all get tired, we all get weary. In fact, if you never feel like giving up, then your dreams are too small. If you never feel like quitting, then you need to set some larger goals. When that pressure comes to get discouraged and to think about how you can’t take it anymore, that is completely normal. Every person feels that way at times."

At  least I know what I'm feeling is not too abnormal.