You should keep going forward, starting to redo stuff is the best way to get stuck !
As you keep drawing, you will keep getting better and will keep wanting doing the best and wish you had done it better before, see the loop ?
I have a friend who is never satisfied with the look of his main character, for a time he kept redrawing it and so , in the same amount f time ,while I had 60 pages of a story, he had 4 (granted he is a bit extreme of an exemple but my point still stands I think).