I know there is little time left. Though, I wanted to point you in a direction that better translate paper drawn stuff in to digital without having to struggle to cookie cut the stuff out.

Put the paper drawn stuff on a higher layer, (optional but suggested: desaturate the layer.) then put the layer on MULTIPLY. What normally happens is, the white disappears and the darker parts like the line art stays. It saves a lot of time.

This is for a next time, since there is little time left.

(P.S. I started my journey on paper drawing too and scanning it.)