There's an episode of MTS where eddie does a seminar at 10th planet saint paul and a white belt comes up with an easier way to get to double bagger for people having trouble. Might could check it out playa', see if it helps.
I'm 5'1 and I can't double bag unless I have the person really far down in my guard then I have to swing my leg I'm double bagging with waay out so I get really high on their shoulder. I don't know if that helps but I feel your frustration, I'm always the smallest person at HQ lol
“It's supposed to be hard. If it wasn't hard, everyone would do it. The hard ... is what makes it great.”