I guess that's your dad's way of dealing with things. Either that or he just doesn't know enough about depression. My parents thought that way too.. that it's all my fault and there's something wrong and so it's not depression. Until my doctor had to educate them (I failed at it) and so they were HALF-convinced.
If you think you need treatment, that's the first step towards recovery. Have you tried again? Or maybe confide in your mom, if your dad is kinda hard to get through?

go for it! No harm visiting the doc's...
__________________
"The is no better exercise for the human heart than reaching and lifting others up." - John Holmes
herethennow: This ward is a prison!
Wardmate: No.. here's not a prison. *points to brain* Here is.
dx: recurrent MDD.