For a good bending exercise, while you are warming up at the walk, ride squares. Using your outside rein and leg, ask the horse to make a nice sweeping turn, then go straight until you are ready to make your next turn, and repeat outside leg/rein turn. Keep your inside leg soft for your horse to bend around and only use the inside rein as a flexion rein if you absolutely need it. Once your horse starts to bend through his body to make the turns, he will start to stretch into the reins. Obviously you need some rein contact to do this exercise. You can't make the turns with the reins in your lap, so this will help you keep your hands forward and the contact soft and spongy. Once your horse starts to bend through his body to make the turns, he will start to stretch into the reins, and you will be delighted to find a nice soft horse where that 2x4 used to be. Your position is good to go, so it's just a matter of unlocking your horse's stiff parts.
You just have to see your distance...you don't have to like it.