The damage to the trunk may have been mechanical damage or a possible canker we cannot say for sure. There is nothing that can be done to save the tree. The majority of the tree is dead. It will limp along but never return to its former glory. You should remove and replant.
Tree fruits, in general, are a challenge to grow as they are so susceptible to insect and disease issues and require a spray schedule for control.
Consider some of the small fruits like blueberry, blackberry, or plant an ornamental tree.