Net the tree before the cherries start to ripen. If the tree is too big for this plant a new tree next year, possibly bare root, and cut it off a knee height. I know, it broke my heart too. This will cause the tree to grow branches (develop a scaffold) starting where the cut was made. Then continue to prune new growth to keep the tree about six feet high. At this height you will always be able to net the tree and reach all the fruit. Let the birds feast on the fruit off the old tree.