There's another way to edit the sentence, which is to add a comma before the second 'which.' The survivor is struggling toward 'some resolution,' not a specific resolution that the mind may never find. The final clause is an appended thought, not a conclusion of the previous clause: 'Death ends a life, but it does not end a relationship, which struggles on in the survivor's mind toward some resolution, which it may never find.'
Robert AndersonThat Jesus of Nazareth died upon a cross is mere matter of history; that He who did so die was the Christ the Son of God is entirely a matter of revelation.
Robert AndersonIn every marriage more than a week old, there are grounds for divorce. The trick is to find, and continue to find, grounds for marriage.
Robert Anderson