The big problem with being a Sunday School leader is when you are teaching the children about living a good, Christian life - praying, reading the bible, following Christ, including Him in your life - knowing full well that one is rubbish at doing these things yourself. Leading by the book, and not by example.
Option 1 - resign from being a Sunday School leader
Option 2 - make a proper effort to try and do what you know to be right - praying, reading the Bible, folllowing Christ, including Him in your life
Option 3 - do nothing; just carry on and ignore the issue.
I'll try Option 2. Seems like a really good idea to me.