If you find it hard to pull your needle through the fabric (densely worked stitches and canvas can always be troublesome!) why not try out these special grip thimbles? Put on your finger and thumb and grip the needle with ease every time. They are thin so you still have sensitivity in your fingers to carry on sewing as normal!
There are three sizes in a pack, 14mm, 16mm and 18mm and they also stretch to make a good fit.