I was stuck in this rut for awhile too where I couldn't see past any of the negativity and really labeled myself with my issues. I like that someone brought it up to you and gave you ways to fight it. I will admit, the 10 good things about yourself challenge actually is very helpful... Even if it is hard, it is worth it. I ended up doing it and drawing images by each point I made just for the extra awesome factor. Seemed to help.
Good luck to you and doing this...