EasyPeezy

You don't need to hold all the bulk. (You would need very large hands to do that. LOL)
Try to grab enough of the quilt on each side of the needle, sew (about an arm's length
then stop. Move your hands and grab some more and feed it through.
If you are not comfortable grabbing the top, grab it from the bottom.
Just concentrate on the part you are going to sew. The rest of the quilt should
be supported by tables. I put an ironing board to my left with a big table
further left and another big table in front all level with my sewing machine
table. Hope this helps.

Edit: Your hands should make a triangle with the needle. You move your
hands towards the needle then move your hands back and do it again.