It may have helped that all the bad I have thus-far undone was caused by the object of my hate, and so motivation was easy to come by.

There is no way to discard hate. You can certainly move on, occupy yourself with other matters, but that hurt will always be there. Think of it as a wound: no matter how deep, it will eventually heal over and leave a scar. I'm afraid all you can do is learn to live with it.