Perfectionism was a huge issue for us with DS6 when he was that age. We did the same thing, alternated helping, drawing or taking no role at all. At 22mos. he discovered writing the alphabet and all drawing went out the window for awhile while he learned how to write. Once he came back around to pictures, it wasn't such an issue.

Shari
Mom to DS 10, DS 11, DS 13
Ability doesn't make us, Choices do!