Learning Mandarin is just like everything else in life. There will be times that you feel terrible about yourself, or you are too distracted by other things.
The way to handle it is also the same way to handle other inevitable bumps: Stick to your road map. Summon your extra strength to put one foot in front of another. Hang in there.
When the dark time is over, you will be happy that you didn't give up. You carried on.
